Compositions and methods for treating metabolic disorders

ABSTRACT

Methods for improving the gastrointestinal tolerability of biguanide compounds and for treating metabolic disorders and/or inducing weight loss in patients in need thereof particularly in individuals having a contraindication for treatment with biguanide compounds, are provided comprising administering delayed release formulations of such biguanide compounds, including metformin, targeted to the small intestine.

FIELD OF THE INVENTION

The present invention relates generally to the treatment of metabolicdisorders with biguanide compounds, and to improving thegastrointestinal tolerability of such compounds, by administeringbiguanide compounds to patients using delayed-release formulations.

BACKGROUND OF THE INVENTION

Hyperglycemia, hyperglycaemia, or high blood sugar, is a condition inwhich an excessive amount of glucose, e.g., greater than about 125mg/dL, circulates in the blood plasma. Chronic hyperglycemia at levelsthat are more than slightly above normal can produce a wide variety ofserious complications over a period of years, including kidney damage,neurological damage, cardiovascular damage, damage to the retina, ordamage to the feet and legs. Diabetic neuropathy may be a result oflong-term hyperglycemia.

Hyperglycemia may be caused by or associated with dysfunction of thethyroid, adrenal, and pituitary glands, diseases of the pancreas, severesepsis, and intracranial diseases such as encephalitis, brain tumors,and meningitis. By far the most common cause of chronic hyperglycemia isdiabetes mellitus, which is widely considered by many to be a loominghealth care epidemic. In diabetes mellitus, the hyperglycemia typicallyresults from low insulin levels (type I diabetes) and/or insulinresistance at the cellular level (type II diabetes).

Many type II diabetes medications are designed to lower blood glucoselevels. A first line drug of choice for the treatment of type IIdiabetes, and the most commonly prescribed antidiabetic medication inthe world, is metformin. In contrast to most diabetics medications,hypoglycemia with metformin is rare; it is also weight neutral and isassociated with reduced cardiovascular events and reduced mortality.

Metformin (dimethylbiguanide) belongs to a class of biguanide drugsdeveloped based on a glucose-lowering extract containing guanidines fromthe Galega officinalis plant. (Bailey & Turner Metformin. N Engl J Med.1996 Feb. 29; 334(9):574-9; Bailey et al. Metformin: its botanicalbackground. Practical Diabetes Int. 2004; 21(3): 115-7). Originallysynthesized as a side product in 1921, (Werner E, Bell J. Thepreparation of methylguanidine, and of ββ-dimethylguanidine by theinteraction of dicyanodiamide, and methylammonium and dimethylammoniumchlorides respectively. J Chem Soc, Transactions. 1921; 121:1790-5),metformin and other biguanides were found to lower blood glucose inanimals. Studies on the glucose-lowering effects of metformin,phenformin and buformin in humans were published in the 1950s. At first,the greater potency of phenformin and buformin resulted in their morewidespread use; however, their association with lactic acidosisultimately led to discontinuation in most countries by the end of the1970s.

Metformin improves glucose tolerance in patients by lowering both basaland postprandial plasma glucose. Metformin monotherapy generally lowersfasting blood glucose by 20% and HbA1c levels by approximately 1.5%.(Bailey & Turner, supra; DeFronzo & Goodman Efficacy of metformin inpatients with non-insulin-dependent diabetes mellitus. The MulticenterMetformin Study Group. N Engl J Med. 1995 Aug. 31; 333(9):541-9).Metformin has also been shown to improve serum lipids, decreasingtriglycerides, free fatty acids, and LDL-cholesterol and modestlyincreasing HDL-cholesterol. (Bailey & Turner, supra.)

Metformin's antihyperglycemic effects have been postulated to resultfrom a wide variety of systemic biochemical interactions including,e.g., suppressing glucose production by the liver, increasing insulinsensitivity, enhancing peripheral glucose uptake (by phosphorylatingGLUT-4 enhancer factor), increasing fatty acid oxidation, and/ordecreasing absorption of glucose from the gastrointestinal tract.(Hundal & Inzucchi Metformin: new understandings, new uses. Drugs. 2003;63(18):1879-94). More recently, investigators have focused on itsapparent impact on the secretion of glucagon-like peptide-1 (GLP-1),apparently determining that metformin does not act directly on L cellsin the gut to induce GLP-1 secretion or enhance L cell sensitivity toseveral known secretagogues. (Mulherin et al., Mechanisms underlyingmetformin-induced secretion of glucagon-like peptide-1 from theintestinal L cell. Endocrinology 152:4610-19 (December 2011)). Theseinvestigators suggested that metformin stimulates GLP-1 release throughan indirect mechanism involving both muscarinic (M3) receptor-dependentand Gastrin Releasing Peptide (GRP) pathways independent of intestinal Lcells, such that systemic bioavailability of metformin is critical totherapeutic efficacy.

Unfortunately, however, systemic exposure of metformin still poses aserious risk of lactic acidosis for several patient populations. Lacticacidosis is a potentially fatal metabolic complication that occurs whenlactic acid levels increase in the bloodstream. Accordingly, metforminis contraindicated in people with any condition that could increase therisk of lactic acidosis, including kidney disorders, lung disease, andliver disease. According to the prescribing information, heart failure,in particular, unstable or acute congestive heart failure, alsoincreases risk of lactic acidosis with metformin. Thus, metforminremains unavailable to treat hyperglycemia in patients with thesecontraindications.

Moreover, conventional metformin formulations often producedose-limiting adverse gastrointestinal (GI) complications includingdiarrhea, nausea, vomiting, dizziness, headaches and dyspepsia.Accordingly, patient administration is generally titrated upward over aperiod of time to a maximum tolerated dose based in not insignificantpart on any resulting patient-specific adverse GI effects.Extended-release formulations have been developed in the hopes ofaddressing this, but have not adequately resolved these problems.

Clearly, there continues to be a need for better and safer compositionsand methods for delivering biguanide compounds that address thesetolerability and safety concerns. Ideally, these would also provide moreeffective treatment options for metabolic disorders in patients havingcontraindications for metformin and/or other biguanides.

SUMMARY OF THE INVENTION

As demonstrated herein for the first time, the present inventors havesurprisingly discovered that the systemic bioavailability of biguanidessuch as metformin can be minimized without compromising theirtherapeutic efficacy. Correspondingly, methods and compositions areprovided for the treatment of metabolic disorders in patients, includingotherwise contraindicated patient populations, by administeringdelayed-release (DR) formulations to minimize the systemicbioavailability of the biguanide compound in the patient.

Also demonstrated herein for the first time is the surprising findingthat GI complications typically resulting from biguanide administrationcan be dramatically reduced using the subject compositions and methods.Accordingly, patient comfort and compliance is greatly improved, as istherapeutic efficacy. Correspondingly, methods and compositions areprovided for improving the GI tolerability of, and/or reducing GIcomplications resulting from, biguanide administration, by administeringdelayed-release formulations comprising a biguanide compound to minimizethe systemic bioavailability of the compound in the patient.

The biguanide compounds of the disclosure may be administered to asubject in need thereof to treat various metabolic disorders, includingobesity, dislipidemia or other disorders of lipid metabolism as well ashyperglycemic conditions and histopathological diseases associated withhyperglycemia, including type II diabetes, prediabetes, gestationaldiabetes and polycystic ovary syndrome. Particularly in view of thesurprising and unexpected decoupling of systemic bioavailability andtherapeutic efficacy achieved herein, and consequent improvement in thetoxicity and safety profile, the effective use of biguanide compoundsfor prophylaxis and prevention of such diseases and disorders, as wellas for more general weight loss purposes in overweight or mildly toseverely obese individuals, is also explicitly contemplated.

Accordingly, in one aspect, provided herein are methods of treatingmetabolic disorders in a patient in need thereof, includingcontraindicated patients, comprising administering a therapeuticallyeffective amount of a biguanide compound to said patient in adelayed-release formulation, wherein said administration minimizes thesystemic bioavailability of the biguanide compound in the patient. Inanother aspect, methods of improving the GI tolerability of biguanidecompounds and/or reducing GI complications resulting from biguanideadministration are provided, comprising administering a therapeuticallyeffective amount of a biguanide compound to a subject in adelayed-release formulation, wherein said administration minimizes thesystemic bioavailability of the biguanide compound in the patient.Suitable biguanide compounds for use in the subject methods include,e.g., metformin, phenformin, buformin or imeglimin, including analogs,salts, solvates, polymorphs, hydrates, N-oxides, and prodrugs of suchcompounds.

In preferred embodiments, the biguanide compound has a reduced relativebioavailability of 70%, 60%, 50%, 40%, 30%, 20% or 10% in the subjectdelayed-release formulation compared to a conventional immediate-release(IR) or extended-release (XR) composition having the same amount of thebiguanide compound. In particular embodiments, administration of thesubject delayed-release formulation minimizes the mean plasma AUC, themean plasma C_(max) and/or the circulating plasma concentration of thebiguanide compound in said patient compared to an identical protocoladministering an IR or XR formulation having the same amount of thebiguanide compound. In preferred embodiments, the biguanide compound ismetformin, the IR composition is Glucophage® and the XR composition isGlucophage® XR.

In one embodiment, the mean plasma AUC₀₋₃₆ of the biguanide compound isless than about 15,000 ng*h/mL or 14,000 ng*h/mL, preferably less thanabout 12,000 ng*h/mL, more preferably less than about 11,000 ng*h/mL or10,500 ng*h/mL, and most preferably less than about 10,000 ng*h/mL whenadministered at 2000 mg total daily dose (TDD) or 1000 mg twice a day(bis in die; abbreviated as “b.i.d” or “BID”). In another embodiment,the mean plasma AUC₀₋₃₆ of the biguanide compound is less than about10,000 ng*h/mL, preferably less than about 9,000 ng*h/mL, morepreferably less than about 8,000 ng*h/mL or 7,000 ng*h/mL, and mostpreferably less than about 6,000 ng*h/mL or 5,000 ng*h/mL whenadministered at 1000 mg TDD, 500 mg BID or lower effective doses.

In one embodiment, the mean plasma C_(max) of the biguanide compound isless than about 1100 ng/mL, preferably less than about 1000 ng/mL, morepreferably less than about 950 ng/mL, and most preferably less thanabout 900 ng/mL when administered at 2000 mg TDD or 1000 mg BID. Inanother embodiment, the mean plasma C_(max) of the biguanide compound isless than about 800 ng/mL, preferably less than about 700 ng/mL, morepreferably less than about 600 ng/mL, and most preferably less thanabout 600 ng/mL or 500 ng/mL when administered at 1000 mg TDD, 500 mgBID or lower effective doses.

In one embodiment, the resulting circulating plasma concentration of thebiguanide compound is below about 5 μg/ml or 4 μg/ml, preferably belowabout 3 μg/ml or 2.5 μg/ml, more preferably below about 2 μg/ml, 1μg/ml, 0.5 μg/ml, or 0.25 μg/ml in the patient.

The methods and compositions disclosed herein are particularly suitablefor patients having a contraindication for the biguanide compound, e.g,metformin, phenformin or buformin. Such contraindication may be ahypoxic condition, impaired lactate clearance, and/or impaired clearanceof the biguanide compound, e.g., impaired metformin clearance.

For example, in one embodiment, the methods disclosed herein may be usedto treat a patient who may have a hypoxic condition, such as but notlimited to respiratory failure and heart failure. In another embodiment,the patient may have impaired lactate clearance. In another embodiment,the patient may suffer from liver failure, which may result in impairedlactate clearance. In another embodiment, the patient may have impairedclearance of the biguanide compound, which may be caused, e.g., by renalimpairment and/or kidney disease. Accordingly, in one embodiment thepatient may have renal impairment. Such renal impairment may be moderateor severe renal impairment, or endstage renal disease. In anotherembodiment, the patient may have kidney disease, which may be chronic.In another embodiment, the patient may have hyperglycemia, which may bechronic, and which may be caused by type II diabetes.

Accordingly, provided herein are methods of treating a renally impairedsubject having diabetes, comprising administering a therapeuticallyeffective amount of a biguanide compound, e.g., metformin, phenformin,buformin, or imeglimin, in a delayed-release formulation to saidsubject. In certain embodiments, the subject has moderate renalimpairment, severe renal impairment, or end stage renal disease. Inother embodiments, the subject has a scrum creatinine concentration ofgreater than 1.2 mg/dL when the subject is malc, or has a serumcreatinine concentration of greater than 1.1 mg/dL when the subject isfemale. In another embodiment, the subject has a decrease in glomerularfiltration rate (GFR) as compared to a normal baseline level. In anotherembodiment, the subject has an increase in urinary protein as comparedto a normal baseline level.

Also provided herein are methods of treating a diabetic subject havingcongestive heart failure, a hypoxic state and/or advanced liver disease,comprising administering a therapeutically effective amount of abiguanide compound, e.g., metformin, phenformin, buformin or imeglimin,in a delayed-release formulation to said subject.

Another method of treating provided herein is a method of reducing theonset of diabetes in a subject with pre-diabetes, comprisingadministering a therapeutically effective amount of a biguanidecompound, e.g., metformin, phenformin, buformin or imeglimin, in adelayed-release formulation to said subject.

Also provided herein are methods of inducing weight loss in a subject,comprising administering a therapeutically effective amount of abiguanide compound in a delayed-release formulation to said subject. Insome embodiments, the weight loss induced results in over 5 pounds lostin the subject, e.g., over 10 pounds lost, preferably over 25 poundslost, and even more preferably over 50 pounds lost. In otherembodiments, the induced weight loss results in the subject having abody mass index between 18.5 and 24.9. In another embodiment, the weightloss induced results in at least a loss of at least 0.5 inches in thewaist circumference.

Administration of the subject formulations may be twice daily (b.i.d.),in the morning and evening, or once daily (omni in die, abbreviated as“OD”). In certain preferred embodiments, administration may be oncedaily in the morning, e.g., before 1 pm, preferably before 12 noon or 11am, more preferably before 10 or 9 am, or with the morning meal. Inother preferred embodiments, administration may be once daily in theevening, e.g., after 5 pm, more preferably after 6 pm or 7 pm, or withthe evening meal. In another preferred embodiment, administration may beonce daily at bedtime.

The subject methods administer therapeutically effective amounts of thebiguanide compound(s). Notably, however, the inventive methods providedherein advantageously allow for lower therapeutic doses than prior artformulations, both on a per unit basis and/or on a daily dose basis. Incertain embodiments of the methods disclosed herein, the biguanidecompound is administered twice daily in an oral dosage form at a perunit dose greater than 500 mg BID, e.g. 600 or 800 mg BID. In certainpreferred embodiments of the methods disclosed herein, the twice dailyoral dosage is less than 500 mg BID, e.g., less than 400 mg BID, e.g.,less than 300 mg BID, e.g., about 150, 200 or 250 mg BID. In alternativepreferred embodiments, the biguanide compound is administered once a dayat a per unit dose of 75 mg OD, 125 mg OD, 250 mg OD, 300 mg OD, 500 mgOD, 600 mg OD, 750 mg OD, 800 mg OD. or 1000 mg OD. In additionalembodiments, the total daily dose (TDD) of the biguanide compound isless than 2000 mg/day, preferably less than 1500 mg/day, more preferablyless than 1000 or 750 mg/day, most preferably less than 500, 400, 300,or 200 mg/day.

In any of the methods disclosed herein, the delayed-release formulationsmay be enterically coated. In one embodiment, the biguanide compound istargeted for delivery to the small intestine, and the formulationcomprises an oral dosage form enterically coated at a pH at or above5.0, 5.5, or 6.0, e.g., a pH 5.0 enteric coating, a pH 5.5 entericcoating, a pH 6.0 enteric coating, a pH 6.5 enteric coating, or a pH 7.0enteric coating, or combinations thereof. In another embodiment, theoral dosage form may further comprise an extended-release component forthe biguanide compound. In preferred embodiments, the biguanide compoundis targeted for delivery to the distal small intestine, and theformulation comprises an oral dosage form enterically coated at a pH ator above 6.0 or 6.5.

In the methods disclosed herein, the biguanide compound may be orcomprise metformin, a metformin salt, solvate, polymorph, hydrate,N-oxide or prodrug. In preferred embodiments, the biguanide compound isa metformin salt selected from the group consisting of hydrochloride,phosphate, sulfate, hydrobromide, salicylate, maleate, benzoate,succinnate, ethanesulfonate, fumarate, glycolate, palmoate, oratate,acetate, isobutyrate, acetylsalicylate, nicotinic acid, adamantoate,zinc-chlorophylin, carboxylic acid, benzoic acid, dichloroacetic acid,theophylin-7-acetate, clofibrate, tartate, oxalate, tannate and hydroxylacid. In a particularly preferred embodiment, the biguanide compound ismetformin hydrochloride.

The methods disclosed herein may also further comprise theadministration of an immediate-release, extended release ordelayed-release formulation of one or more additional therapeuticagents, e.g., a DPP-IV inhibitor (e.g., sitagliptin, saxagliptin,berberine, vildagliptin, linagliptin, alogliptin, and the like), achemosensory receptor ligand (e.g., a sweet receptor ligand, bitterreceptor ligand, umami receptor ligand, sour receptor ligand, fatreceptor ligand or bile acid receptor ligand), an anti-obesity oranti-diabetes agent, or a chemosensory receptor antagonist, e.g.,lactisole. Non-limiting examples include embodiments further comprisingthe administration of 100 mg sitagliptin OD, or 50 mg sitagliptin BID.The delayed-release formulation can be a bilayer tablet, or a capsulewith the two components as encapsulated mini-tablets. Thedelayed-release formulation may also further comprise an immediaterelease component that has a pH 5.0 enteric coating for the additionaltherapeutic agent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the design of the study described in Example 1.

FIG. 2 shows the events during the treatment period of the studydescribed in Example 1.

FIG. 3 shows the plasma concentration of metformin immediate-release(Metformin IR) (●) and metformin delayed-release (Metformin DR) (▴)(x-axis; ng/mL) as a function of time (y-axis; min) after ingestion att=−240 and after a meal at t=0 min.

FIG. 4A shows the plasma concentration of PYY (x-axis; pg/mL) as afunction of time (y-axis; min) in subjects at baseline (□,∘) or afteringestion of either Metformin IR (●) or Metformin DR (▪) and after ameal at t=0 min. FIG. 4B shows the plasma concentration of active GLP-1(x-axis; GLP-1A pmol/L) as a function of time (y-axis; min) in subjectsat baseline (□,∘) or after ingestion of either Metformin IR (●) orMetformin DR (▪) and after a meal at t=0 min. FIG. 4C shows the plasmaconcentration of total GLP-1 (x-axis; GLP-1T pmol/L) as a function oftime (y-axis; min) in subjects at baseline (□,∘) or after ingestion ofeither Metformin IR (●) or Metformin DR (▪) and after a meal at t=0 min.For FIGS. 4A-4C, percent increase in Abs AUC is compared to baselinevalues.

FIG. 5A shows the plasma concentration of glucose (x-axis; mg/dL) as afunction of time (y-axis; min) in subjects at baseline (□,∘) or afteringestion of either Metformin IR (●) or Metformin DR (▪) and after ameal at t=0 min. FIG. 5B shows the plasma concentration of insulin(x-axis; pmol/L) as a function of time (y-axis; min) in subjects atbaseline (□,∘) or after ingestion of either Metformin IR (●) orMetformin DR (▪) and after a meal at t=0 min. For FIGS. 5A-5B, percentdecrease in Abs AUC is compared to baseline values.

FIG. 6 is a graph that shows the area under the curve of PYY (x-axis;log transformed) as a function of the area under the curve of metformin(ng/mL*min) after ingestion of Metformin IR (●) and Metformin DR (▪).

FIG. 7A shows the plasma concentration of Metformin IR (●) and MetforminDR (▪) (x-axis; ng/mL) as a function of time (y-axis; min) afteringestion at t=−240 and after a meal at t=0 min. FIG. 7B shows theplasma concentration of PYY (x-axis; pg/mL) as a function of time(y-axis; min) in subjects at baseline (□,∘) or after ingestion of eitherMetformin IR (●) or Metformin DR (▪) and after a meal at t=0 min.

FIG. 8 shows the mean plasma metformin concentrations (x-axis; ng/mL) atDay 5 of 500 mg (♦) and 1000 mg (▪) Metformin DR, 1000 mg Metformin IR(∘), and 500 mg Metformin IR+1000 mg Metformin DR (▴) as a function oftime (y-axis; min). Dose was administered at t=−1 minute.

FIG. 9 shows the steady-state relative bioavailability in subjects withtype 2 diabetes of 500 mg BID and 1000 mg BID of Metformin DR comparedto 1000 mg BID of Metformin IR based on the 11 hour plasma metformin AUCon Day 5 (y-axis; % AUC_((0-11hr))). These levels constitute a 45% and57% reduction in the overall plasma metformin extent of exposure for 500mg BID and 1000 mg BID of Metformin DR compared to 1000 mg BID ofMetformin IR.

FIG. 10 shows the mean plasma PYY total concentrations (x-axis; pg/mL)as a function of time (y-axis; min) in subjects at baseline (∘) or Day 5of the designated treatment (●).

FIG. 11 shows the mean plasma GLP-1 active concentration (x-axis;pmol/L) as a function of time (y-axis; min) in subjects at baseline (∘)or Day 5 of the designated treatment (●). Breakfast was administered att=0 min, dose was administered at t=−1 minute, and lunch wasadministered at t=300 min.

FIG. 12 shows the mean plasma glucose concentration (x-axis; mg/dL) as afunction of time (y-axis; min) in subjects at baseline (∘) or Day 5 ofthe designated treatment (●).

FIG. 13 shows the individual change in fasting plasma glucoseconcentrations (x-axis; mg/dL) as a function of time (y-axis; min) frombaseline to Day 5 by scatterplot in subjects treated with 500 mg (♦) and1000 mg (▪) Metformin DR, 1000 mg Metformin IR (●), and 500 mg MetforminIR+1000 mg Metformin DR (▴)(y-axis) The line in the panel marks the LSMean Change in glucose (mg/dL) for each treatment.

FIG. 14 shows the mean plasma metformin concentration (x-axis; ng/mL) of500 mg (♦) and 1000 mg (▪) Metformin DR, 1000 mg Metformin IR (∘), and2000 mg metformin extended release (Metformin XR) a function of time(y-axis; hours). Dose was administered at t=0 hours. Second dose wasadministered for BID regimens at t=12 hours. Meals/snacks were providedat t=−0.42, 2.08, 11.5, 18 and 24 hours.

FIG. 15 shows the C_(max) (left panel) and AUC₀₋₃₆ (right panel) of oneday's dosing of 1000 mg BID metformin IR, 500 mg BID and 1000 mg BID ofMetformin DR and 2000 mg QD metformin XR. The * signifies astatistically significant reduction in exposure compared to bothmetformin IR and metformin XR (all p<0.0001)

FIG. 16 shows the relative bioavailability of one day's dosing of 500and 1000 mg BID Metformin DR compared to 1000 mg BID Metformin IR (leftpanel) and the relative bioavailability of one day's dosing of 500 and1000 mg BID Metformin DR compared to 2000 mg QD Metformin XR (rightpanel)

DETAILED DESCRIPTION

Contemplated herein are methods and compositions that minimize thesystemic bioavailability of biguanide compounds, such as metformin, insubjects yet still provide significant salutary metabolic effects, e.g.reducing hyperglycemia. Contrary to conventional understanding (see,e.g. Mulherin et al, supra), the biguanide compounds of the disclosureactually cause release of GLP-1 through a mechanism of action which mayinclude interaction with the luminal or epithelial aspect (i.e., thegastrointestinal tract side) of enteroendocrine cells, and systemicbioavailability can therefore be minimized while still achievingmeaningful therapeutic efficacy. Advantageously, the subject methods andcompositions significantly improve GI tolerability and also reduce thepossibility of adverse effects such as lactic acidosis, such thatotherwise contraindicated patients can now be effectively treated.

Accordingly, provided herein are methods of improving the GItolerability of biguanide compounds, and/or reducing GI complicationsresulting biguanide compound administration, comprising administering atherapeutically effective amount of a biguanide compound in adelayed-release formulation to a subject in need thereof; wherein saiddelayed-release formulation minimizes the systemic level of the compoundin the subject. Also provided herein are methods of treating metabolicdisorders in subjects, and particularly in subjects having acontraindication for biguanide compound(s), comprising administering atherapeutically effective amount of a biguanide compound in adelayed-release formulation to a subject in need thereof; wherein saiddelayed-release formulation minimizes the systemic level of the compoundin the subject. In preferred embodiments, the biguanide compound isselected from the group consisting of metformin, buformin, phenforminand imeglimin, and is administered at lower doses and/or with lowerbioavailability than currently indicated while still achieving thedesired metabolic improvements.

Definitions

The terms “gastrointestinal tract” and “gut,” as used herein, refer tothe stomach and intestine. The “small” or “upper” intestine includes theduodenum, jejunum and ileum and the “large” or “lower” intestineincludes the caecum, colon and rectum. The “distal” small intestineincludes the jejunum and ileum.

“Treating” or “treatment” of any condition, disease or disorder refers,in some embodiments, to ameliorating the disease, disorder, or condition(i.e., arresting or reducing the development of the disease, disorder,or condition, or at least one of the clinical symptoms thereof). Inother embodiments “treating” or “treatment” refers to ameliorating atleast one physical parameter, which may or may not be discernible by thesubject, including physical parameters that are undesired but notclinically significant. In yet other embodiments, “treating” or“treatment” refers to inhibiting the disease, disorder, or condition,either physically, (e.g., stabilization of a discernible symptom),physiologically, (e.g., stabilization of a physical parameter) or both.In yet other embodiments, “treating” or “treatment” refers to preventingor to delaying the onset of the disease, disorder, or condition.

“Therapeutically effective amount” or “effective amount” means theamount of a composition, compound, therapy, or course of treatment that,when administered to a subject for treating a discase, disorder, orcondition, is sufficient to effect such treatment for the disease,disorder, or condition. The “therapeutically effective amount” will varydepending on the composition, the compound, the therapy, the course oftreatment, the disease, disorder, or condition, and its severity and theage, weight, etc., of the subject to be treated.

When the biguanide compounds described herein include one or more chiralcenters, the stereochemistry of such chiral centers can independently bein the R or S configuration, or a mixture of the two. The chiral centerscan be further designated as R or S or R,S or d,D, 1,L or d,l, D,L.Correspondingly, the biguanide compounds of the invention, if they canbe present in optically active form, can actually be present in the formof a racemic mixture of enantiomers, or in the form of either of theseparate enantiomers in substantially isolated and purified form, or asa mixture comprising any relative proportions of the enantiomers.

When the biguanide compounds described herein contain two or more chiralcenters then diastereomers are possible. Such diastereomers may bepresent as pure diastereomeric enantiomers, pure racemic mixtures ofdiastereomeric enantiomers, mixtures of diastereomers which may beracemic or may have optical activity in their own right due to complexpermutations of enantiomeric diastereomers in the balance of themixtures.

When the biguanide compounds of the invention, if they can be present ingeometrically isomeric forms around, for example, the guanide bond, thenthey can actually be present in the form of a mixture of geometricisomers comprising any relative proportions of the isomers, or in somecases in the form of either of the separate geometric isomers insubstantially isolated and purified form.

When the biguanide compounds described herein include one or moreisolated or linearly conjugated double bonds, the geometry around suchdouble bonds can be independently a cis/trans, E/Z mixture or an E or Zgeometric isomer thereof.

“Alkyl” means a straight or branched chain, saturated monovalenthydrocarbon radical. By way of example, the hydrocarbon chain may havefrom one to twenty carbons, one to sixteen carbons, one to fourteencarbons, one to twelve carbons, one to ten carbons, one to eightcarbons, one to six carbons, one to four carbons, etc. “Lower alkyl” mayrefer to alkyls having, e.g., one to six carbons, one to four carbons,etc. In certain examples, an straight chain alkyl may have from one tosix carbon atoms and a branched alkyl three to six carbon atoms, e.g.,methyl, ethyl, propyl, 2-propyl, butyl (including all isomeric forms),pentyl (including all isomeric forms), and the like. “Me” means methyl,“Et” means ethyl, and “iPr” means isopropyl.

“Aryl” means a monovalent monocyclic or bicyclic aromatic hydrocarbonradical, e.g., having from of 6 to 20 or 6 to 10 ring atoms e.g., phenylor naphthyl.

“Alkylaryl” means a (alkylene)-R radical where R is aryl as definedabove.

“Cycloalkyl” means a cyclic saturated or partially saturated monovalenthydrocarbon radical (or an alicyclic radical). By way of example, thecycloalkyl may have from three to twenty carbon atoms, from three tosixteen carbon atoms, from three to fourteen carbon atoms, from three totwelve carbon atoms, from three to ten carbon atoms, from three to eightcarbon atoms, from three to six carbon atoms, etc., wherein one or twocarbon atoms may be replaced by an oxo group, e.g., admantanyl,cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclohexenyl, indanyland the like.

“Alkylcycloalkyl” means a (alkylene)-R radical where R is cycloalkyl asdefined above; e.g., cyclopropylmethyl, cyclobutylmethyl,cyclopentylethyl, or cyclohexylmethyl, and the like.

“Heterocyclyl” or “heterocycloalkyl” means a saturated or unsaturatedmonovalent monocyclic group, in which one or two ring atoms areheteroatom selected from N, O, or S, the remaining ring atoms being C.The heterocyclyl ring is optionally fused to a (one) aryl or heteroarylring as defined herein. The heterocyclyl ring fused to monocyclic arylor heteroaryl ring is also referred to in this Application as “bicyclicheterocyclyl” ring. Additionally, one or two ring carbon atoms in theheterocyclyl ring can optionally be replaced by a —CO— group. Morespecifically the term heterocyclyl includes, but is not limited to,pyrrolidino, piperidino, homopiperidino, 2-oxopyrrolidinyl,2-oxopiperidinyl, morpholino, piperazino, tetrahydropyranyl,thiomorpholino, and the like. When the heterocyclyl ring is unsaturatedit can contain one or two ring double bonds. When the heterocyclyl groupcontains at least one nitrogen atom, it is also referred to herein asheterocycloamino and is a subset of the heterocyclyl group. When theheterocyclyl group is a saturated ring and is not fused to aryl orheteroaryl ring as stated above, it is also referred to herein assaturated monocyclic heterocyclyl.

“Alkylheterocycloalkyl” means a ˜(alkylene)-R radical where R isheterocyclyl ring as defined above e.g., tetraydrofuranylmethyl,piperazinylmethyl, morpholinylethyl, and the like.

“Heteroaryl” means a monovalent monocyclic or bicyclic aromatic radical,where one or more, preferably one, two, or three, ring atoms areheteroatom selected from N, O, or S, the remaining ring atoms beingcarbon. Representative examples include, but are not limited to,pyrrolyl, thienyl, thiazolyl, imidazolyl, furanyl, indolyl, isoindolyl,oxazolyl, isoxazolyl, diazolyl, pyrazolyl, triazolyl, benzothiazolyl,benzoxazolyl, quinolinyl, isoquinolinyl, pyridinyl, pyrimidinyl,pyrazinyl, pyridazinyl, tetrazolyl, and the like.

“Oxo” or “carbonyl” means=(O) group or C═O group, respectively.

The term “substituted” means that the referenced group is substitutedwith one or more additional group(s) individually and independentlyselected from groups described herein. In some embodiments, an optionalsubstituent is selected from oxo, halogen, —CN, —NH₂, —OH, —NH(CH₃),—N(CH₃)₂, alkyl (including straight chain, branched and/or unsaturatedalkyl), substituted or unsubstituted cycloalkyl, substituted orunsubstituted heterocycloalkyl, fluoroalkyl, substituted orunsubstituted heteroalkyl, substituted or unsubstituted alkoxy,fluoroalkoxy, —S-alkyl, —S(O)₂-alkyl, —CONH((substituted orunsubstituted alkyl) or (substituted or unsubstituted phenyl)), —CON(Hor alkyl)₂, —OCON(substituted or unsubstituted alkyl)₂,—NHCONH((substituted or unsubstituted alkyl) or (substituted orunsubstituted phenyl)), —NHCOalkyl, —N(substituted or unsubstitutedalkyl)CO(substituted or unsubstituted alkyl), —NHCOO(substituted orunsubstituted alkyl), —C(OH)(substituted or unsubstituted alkyl)₂, and—C(NH₂)(substituted or unsubstituted alkyl)₂. In some embodiments, byway of example, an optional substituent is selected from oxo, fluorine,chlorine, bromine, iodine, —CN, —NH₂, —OH, —NH(CH₃), —N(CH₃)₂, —CH₃,—CH₂CH₃, —CH(CH₃)₂, —CF₃, —CH₂CF₃, —OCH₃, —OCH₂CH₃, —OCH(CH₃)₂, —OCF₃,—OCH₂CF₃, —S(O)₂—CH₃, —CONH₂, —CONHCH₃, —NHCONHCH₃, —COCH₃, —COOH andthe like. In some embodiments, substituted groups are substituted withone, two or three of the preceding groups. In some embodiments,substituted groups are substituted with one or two of the precedinggroups. In some embodiments, substituted groups are substituted with oneof the preceding groups. Further, unless stated to the contrary, aformula with chemical bonds shown only as solid lines and not as wedgesor dashed lines contemplates each possible isomer, e.g., each enantiomerand diastereomer, and a mixture of isomers, such as racemic or scalemicmixtures.

In some embodiments, a biguanide compound of the disclosure is presentin a composition as a salt. In some embodiments, salts are obtained byreacting a compound of the disclosure with acids. In some otherembodiments, pharmaceutically acceptable salts are obtained by reactinga compound of the disclosure with a base. In other embodiments, thecompounds are used as free-acid or free-base form in the manufacture ofthe compositions described herein. The type of salts, include, but arenot limited to: (1) acid addition salts, formed by reacting the freebase form of the compound with a pharmaceutically acceptable: inorganicacid, such as, for example, hydrochloric acid, hydrobromic acid,sulfuric acid, phosphoric acid, metaphosphoric acid, and the like; orwith an organic acid, such as, for example, acetic acid, propionic acid,hexanoic acid, cyclopentanepropionic acid, glycolic acid, pyruvic acid,lactic acid, malonic acid, succinic acid, malic acid, maleic acid,fumaric acid, trifluoroacetic acid, tartaric acid, citric acid, benzoicacid, 3-(4-hydroxybenzoyl)benzoic acid, cinnamic acid, mandelic acid,methanesulfonic acid, ethanesulfonic acid, 1,2-ethanedisulfonic acid,2-hydroxyethanesulfonic acid, benzenesulfonic acid, toluenesulfonicacid, 2-naphthalenesulfonic acid,4-methylbicyclo-[2.2.2]oct-2-ene-1-carboxylic acid, glucoheptonic acid,4,4′-methylenebis-(3-hydroxy-2-ene-1-carboxylic acid), 3-phenylpropionicacid, trimethylacetic acid, tertiary butylacetic acid, lauryl sulfuricacid, gluconic acid, glutamic acid, hydroxynaphthoic acid, salicylicacid, stearic acid, muconic acid, butyric acid, phenylacetic acid,phenylbutyric acid, valproic acid, and the like; (2) salts formed whenan acidic proton present in the parent compound is replaced by a metalion, e.g., an alkali metal ion (e.g. lithium, sodium, potassium), analkaline earth ion (e.g. magnesium, or calcium), or an aluminum ion. Insome cases, the biguanide compound described herein are reacted with anorganic base, such as, but not limited to, ethanolamine, diethanolamine,triethanolamine, tromethamine, N-methylglucamine, dicyclohexylamine,tris(hydroxymethyl)methylamine. In other cases, the compounds describedherein form salts with amino acids such as, but not limited to,arginine, lysine, and the like. Acceptable inorganic bases used to formsalts with compounds that include an acidic proton, include, but are notlimited to, aluminum hydroxide, calcium hydroxide, potassium hydroxide,sodium carbonate, sodium hydroxide, and the like.

The term “amino acid” includes any one of the twenty naturally-occurringamino acids or the D-form of any one of the naturally-occurring aminoacids. In addition, the term “amino acid” also includes othernon-naturally occurring amino acids besides the D-amino acids, which arefunctional equivalents of the naturally-occurring amino acids. Suchnon-naturally-occurring amino acids include, for example, norleucine(“Nle”), norvaline (“Nva”), L- or D-naphthalanine, ornithine (“Orn”),homoarginine (homoArg) and others well known in the peptide art, such asthose described in M. Bodanzsky, “Principles of Peptide Synthesis,” 1stand 2nd Revised Ed., Springer-Verlag, New York, N.Y., 1984 and 1993, andStewart and Young, “Solid Phase Peptide Synthesis,” 2nd Ed., PierceChemical Co., Rockford, Ill., 1984, both of which are incorporatedherein by reference.

Amino acids and amino acid analogs can be purchased commercially (SigmaChemical Co.; Advanced Chemtech) or synthesized using methods known inthe art.

In the scope of the embodiments, the biguanide compounds describedherein include further forms of the compounds such as pharmaceuticallyacceptable salts, solvates (including hydrates), amorphous phases,partially crystalline and crystalline forms (including all polymorphs),prodrugs, metabolites, N-oxides, isotopically-labeled, epimers, pureepimers, epimer mixtures, enantiomers including but not limited tosingle enantiomers and enantiomeric diastereomers, meso compounds,stereoisomers, racemic mixtures and diasteroisomeric mixtures. Biguanidecompounds described herein having one or more double bonds includecis/trans isomers, E/Z isomers and geometric isomers. Biguanidecompounds described herein can be prepared as a pharmaceuticallyacceptable salts formed when an acidic proton present in the parentcompound either is replaced by a metal ion, for example an alkali metalion, an alkaline earth ion, or an aluminum ion; or coordinates with anorganic base. In addition, the salt forms of the disclosed compounds canbe prepared using salts of the starting materials or intermediates.

In some embodiments, the biguanide compounds described herein includesolvent addition forms or crystal forms thereof, particularly solvatesor polymorphs. Solvates contain either stoichiometric ornon-stoichiometric amounts of a solvent, and may be formed during theprocess of crystallization with pharmaceutically acceptable solventssuch as water, ethanol, and the like. Hydrates are formed when thesolvent is water, or alcoholates are formed when the solvent is alcohol.

As noted above, in some embodiments the biguanide compounds describedherein possess one or more stereocenters and each center existsindependently in either the R or S configuration. The biguanidecompounds presented herein include all diastereomeric, enantiomeric, andepimeric forms as well as the appropriate mixtures thereof.

In some embodiments, sites on the biguanide compounds disclosed hereinare susceptible to various metabolic reactions. Therefore incorporationof appropriate substituents at the places of metabolic reactions willreduce, minimize or eliminate the metabolic pathways. In specificembodiments, the appropriate substituent to decrease or eliminate thesusceptibility of the aromatic ring to metabolic reactions is, by way ofexample only, a halogen, deuterium or an alkyl group.

In some embodiments, the biguanide compounds described herein areisotopically-labeled, which are identical to those recited in thevarious formulae and structures presented herein, but for the fact thatone or more atoms are replaced by an atom having an atomic mass or massnumber different from the atomic mass or mass number usually found innature. In some embodiments, one or more hydrogen atoms are replacedwith deuterium. In some embodiments, metabolic sites on the compoundsdescribed herein are deuterated. In some embodiments, substitution withdeuterium affords certain therapeutic advantages resulting from greatermetabolic stability, such as, for example, increased in vivo half-lifeor reduced dosage requirements. Throughout the specification, groups andsubstituents thereof can be chosen by one skilled in the field toprovide stable moieties and compounds.

Biguanides

The compositions and methods disclosed herein relate to metformin andother biguanides. By way of background, metformin is one of the simpleststructural variants of a class of compounds known as the biguanides.From a structural perspective metformin resembles a pharmacophore orfragment of a larger biologically active chemical structure.

In one embodiment, the biguanide compounds of the subject inventioninclude the following:

wherein:

-   -   R₁, R₂, R₃, R₄, R₅, R₆, and R₇ are independently selected from:    -   H, OH,    -   O-Rx, wherein Rx is alkyl, cycloalkyl, alkylcycloalkyl, acyl,        ester, thioester;    -   optionally substituted alkyl (e.g., a C₁ to C₁₂ straight chain        or branched chain alkyl optionally substituted with oxygen,        silicon, sulphur or optionally substituted with OH, O-alkyl, SH,        S-alkyl, NH₂, NH-alkyl); cycloalkyl (e.g., C₃ to C₇ cycloalkyl);        alkylcycloalkyl (e.g., C₄ to C₁₂ alkylcycloalkyl);        heterocycloalkyl (e.g., where the heterocycle comprises one or        two hetero atoms selected from O, S, or N, including a C₂ to C₆        heterocycloalkyl); alkylheterocycloalkyl (e.g., where the        heterocycle comprises one or two hetero atoms selected from O,        S, or N, including a C₃ to C₁₁ alkylheterocycloalkyl, and        including wherein when N is present in the heterocyclic ring,        the nitrogen atom may be in the form of an amide, carbamate or        urea); optionally substituted alkenyl (e.g., C₁ to C₁₂ straight        chain or branched chain alkenyl optionally substituted with        oxygen, silicon, sulphur or optionally substituted with OH,        O-alkyl, SH, S-alkyl, NH₂, NH-alkyl); optionally substituted        alkynyl (e.g., C₁ to C₁₂ straight chain or branched chain        alkynyl optionally substituted with oxygen, silicon, sulphur or        optionally substituted with OH, O-alkyl, SH, S-alkyl, NH₂,        NH-alkyl);    -   optionally substituted aryl (e.g., phenyl, substituted phenyl,        naphthyl, substituted naphthyl); optionally substituted        alkylaryl (e.g., alkylphenyl, alkylsubstituted phenyl,        alkylnaphthyl, alkylsubstituted naphthyl); optionally        substituted heteroaryl (e.g., pyridyl, furanyl, thiophenyl,        pyrrollyl, oxazolyl, isoxazolyl, thiazolyl, diazolyl, pyrazolyl,        triazolyl all of which are optionally substituted); optionally        substituted alkylheteroaryl; and    -   or R₆ and R₇ may join to form a bond, together forming a ring        including the nitrogen atoms to which they are attached;    -   or R₁ and R₂ may together form a 3 to 8 membered heterocyclic        ring, including the nitrogen atoms to which they are attached;    -   or R₄ and R₅ may together form a ring selected from the group        aziridine, pyrrolyl, imidazolyl, pyrazolyl, indolyl, indolinyl,        pyrrolidinyl, piperazinyl and piperidyl, including the nitrogen        atoms to which they are attached.

In certain embodiments, O-Rx may be selected from: O—C₁ to C₈ straightchain or branched chain alkyl; O—C₃ to C₇ cycloalkyl; O—C₄ to C₈alkylcycloalkyl; O-acyl; O-esters; and O-thioesters.

In other embodiments, optional substitutions may include, e.g., OH,O-alkyl, SH, S-alkyl, NH₂, NH-alkyl. Further, an alkyl, alkenyl,alkynyl, etc. may be substituted with an oxygen, silicon, sulphur, etc.to form a heteroalkyl, heteroalkenyl, heteroalkynyl, etc.

In certain embodiments, each of: R₃, R₆, and R₇, or R₃, R₄, R₅, and R₇,or R₃, R₄, R₅, and R₇, or R₃, R₄, R₅, R₆ and R₇, or R₂, R₃, R₄, R₅, R₆and R₇ are independently selected from:

-   -   H, methyl, ethyl, propyl or isopropyl; and each of the remaining        substituent groups: R₁, R₂, R₄, and R₅, or R₁, R₂, and R₆, or        R₁, R₂, and R₆, or R₁ and R₂, or R₁, respectively, are        independently selected from:    -   H; optionally substituted alkyl (e.g., C₁ to C₁₂ straight chain        or branched chain alkyl optionally hetero substituted with        oxygen, silicon, sulphur or optionally substituted with OH,        O-alkyl, SH, S-alkyl, NH₂, NH-alkyl); optionally substituted        alkenyl (e.g., C₁ to C₁₂ straight chain or branched chain        alkenyl optionally hetero substituted with oxygen, silicon,        sulphur or optionally substituted with OH, O-alkyl, SH, S-alkyl,        NH₂, NH-alkyl); optionally substituted alkynyl (e.g., C₁ to C₁₂        straight chain or branched chain alkynyl optionally hetero        substituted with oxygen, silicon, sulphur or optionally        substituted with OH, O-alkyl, SH, S-alkyl, NH₂, NH-alkyl);        cycloalkyl (e.g., C₃ to C₇ cycloalkyl); alkylcycloalkyl (e.g.,        C₄ to C₁₂ alkylcycloalkyl); heterocycloalkyl (e.g., where the        heterocycle comprises one or two hetero atoms selected from O,        S, or N, including C₂ to C₆ heterocycloalkyl);        alkylheterocycloalkyl (e.g., where the heterocycle comprises one        or two hetero atoms selected from O, S, or N, including C₃ to        C₁₁ alkylheterocycloalkyl, and including wherein when N is        present in the heterocyclic ring, the nitrogen atom may be in        the form of an amide, carbamate or urea); aryl (e.g., phenyl,        substituted phenyl, naphthyl, substituted naphthyl); alkylaryl        (e.g., alkylphenyl, alkylsubstituted phenyl, alkylnaphthyl,        alkylsubstituted naphthyl); heteroaryl (e.g., pyridyl, furanyl,        thiophenyl, pyrrollyl, oxazolyl, isoxazolyl, thiazolyl,        diazolyl, pyrazolyl, triazolyl all of which are optionally        substituted); alkylheteroaryl;    -   or R₁ and R₂ may together form a 3 to 8 membered heterocyclic        ring, including the nitrogen atoms to which they are attached;    -   or R₄ and R₅ may together form a ring selected from the group        aziridine, pyrrolyl, imidazolyl, pyrazolyl, indolyl, indolinyl,        pyrrolidinyl, piperazinyl and piperidyl, including the nitrogen        atoms to which they are attached.

Exemplary compounds and substituents of R₁, R₂, R₃, R₄, R₅, R₆, and R₇of Formula I are shown below. Additional combinations of selections ofsubstituents of R₁, R₂, R₃, R₄, R₅, R₆, and R₇ are envisioned anddisclosed in co-pending U.S. patent application Ser. No. 13/547,022, thedisclosure of which is expressly incorporated by reference herein.

In certain embodiments, the biguanide compounds of Formula I may includean asymmetric center or centers, and may be in the form of a compositionof a racemic mixture, a diastereoisomeric mixture, a single enantiomer,an enantiomeric diastereomer, a meso compound, a pure epimer, or amixture of epimers thereof, etc. Further, the biguanide compounds mayhave one or more double bonds, and may be in a form of a cis/trans, E/Zmixture or an E or Z geometric isomer thereof.

The biguanide compounds of Formula I may also be prepared as a saltform, e.g., pharmaceutically acceptable salts, including suitable acidforms, e.g., salt forms selected from hydrochloride, hydrobromide,acetate, propionate, butyrate, sulphate, hydrogen sulphate, sulphite,carbonate, hydrogen carbonate, phosphate, phosphinate, oxalate,hemi-oxalate, malonate, hemi-malonate, fumarate, hemi-fumarate, maleate,hemi-maleate, citrate, hemi-citrate, tartrate, hemi-tartrate, aspartate,glutamate, etc.

Alternative embodiments of biguanide compounds specifically contemplatedfor use in the subject invention include the related heterocycliccompounds described in co-pending U.S. patent application Ser. No.13/547,022, the disclosure of which is expressly incorporated herein byreference. The phrase “biguanide compound” as used herein includes theserelated heterocyclic compounds, exemplary embodiments of which includethe following:

In one embodiment, the compounds of the disclosure may be prepared as athree component salt form including the components A, B, and C wherein:

-   -   A is the protonated form of a natural or unnatural amino acid;    -   B is the dianion of an acid; and    -   C is the protonated form of a Compound of Formula I.

In certain aspects, stoichiometric amounts of A, B, and C may beincluded wherein:

-   -   A is the protonated form of a natural amino acid selected from        alanine, aspartic acid, asparagine, arginine, glycine,        glutamine, glutamic acid lysine, phenylalanine, tyrosine,        serine, threonine, tryptophan, leucine, isoleucine, histidine,        methionine, proline, cysteine, or cystine;    -   B is the dianion of an acid selected from oxalic, malonic,        citric, maleic, fumaric, tartaric, aspartic, glutamic acids and        the like; and    -   C is the protonated form of a compound of Formula I.

Contraindications for Biguanide Compounds, Including Metformin

Since systemic biguanides, including metformin are reported to besubstantially excreted by the kidney, the risk of the biguanide compoundaccumulation and lactic acidosis increases with the degree of impairmentof renal function. Other contraindications for biguanide compounds suchas metformin include impaired lactate clearance, and a hypoxiccondition. Accordingly, patients having these contraindications are notcurrently treatable with conventional biguanide compounds.

However, as demonstrated herein, the therapeutic efficacy of metforminand other biguanide compounds does not require an increase in thesystemic level of the metformin that presents an increased risk oflactic acidosis. As such, the risk of metformin accumulation and lacticacidosis is dramatically lower, and the methods provided herein cantherefore be used to treat a condition in a patient in need thereof,even where the patient has a contraindication for metformin. Forexample, the methods provided herein may be used to treat a patient inneed thereof, wherein the patient has a hypoxic condition (e.g.,respiratory failure and/or heart failure), impaired lactate clearance(e.g., due to liver failure), impaired metformin clearance, and/or renalimpairment, which may be moderate, severe, or endstage impairment, andmay be the result of chronic kidney disease.

Metabolic Disorders

The compositions and methods of the present invention find advantageoususe in the treatment and/or prophylaxis of metabolic disorders,including being overweight, obesity, prediabetes, Polycystic OvarySyndrome, dislipidemia or disorders of lipid metabolism, as well ashyperglycemic conditions, such as insulin-dependent (type 1) or-independent (type 2) diabetes, as well as physiological conditions ordisorders associated with or that result from the hyperglycemiccondition. Thus, hyperglycemic conditions treatable by a method of theinvention also include a histopathological change associated withchronic or acute hyperglycemia (e.g., diabetes). Particular examplesinclude degeneration of pancreas (β-cell destruction), kidney tubulecalcification, degeneration of liver, eye damage (diabetic retinopathy),diabetic foot, ulcerations in mucosa such as mouth and gums, excessbleeding, delayed blood coagulation or wound healing and increased riskof coronary heart disease, stroke, peripheral vascular disease,dyslipidemia, hypertension and obesity.

As used herein, the term “hyperglycemic” or “hyperglycemia,” when usedin reference to a condition of a patient, means a transient or chronicabnormally high level of glucose present in the blood of a patient. Thecondition can be caused by a delay in glucose metabolism or absorptionsuch that the patient exhibits glucose intolerance or a state ofelevated glucose not typically found in normal patients (e.g., inglucose-intolerant subdiabetic patients at risk of developing diabetes,or in diabetic patients). Fasting plasma glucose (FPG) levels fornormoglycemia are less than about 110 mg/dl, for impaired glucosemetabolism, between about 110 and 126 mg/dl, and for diabetics greaterthan about 126 mg/dl.

Metabolic disorders also include obesity or an undesirable body mass.Leptin, cholecystokinin, PYY and GLP-1 decrease hunger, increase energyexpenditure, induce weight loss or provide normal glucose homeostasis.Thus, in various embodiments, a method of the invention for treatingobesity or an undesirable body mass, or hyperglycemia, involves thelocal administration of metformin to activate enteroendocrine cellproduction of cholecystokinin, oxyntomodulin, GIP, GLP-2, PYY or GLP-1.Disorders treatable also include those typically associated withobesity, for example, abnormally elevated serum/plasma LDL, VLDL,triglycerides, cholesterol, plaque formation leading to narrowing orblockage of blood vessels, increased risk of hypertension/stroke,coronary heart disease, etc.

Synthesis of the Compounds

Compounds described herein may be synthesized using standard synthetictechniques known to those of skill in the art or using methods known inthe art in combination with methods described herein. In additions,solvents, temperatures and other reaction conditions presented hereinmay vary according to the practice and knowledge of those of skill inthe art.

The starting material used for the synthesis of compounds describedherein can be obtained from commercial sources, such as Aldrich ChemicalCo. (Milwaukee, Wis.), Sigma Chemical Co. (St. Louis, Mo.), or thestarting materials can be synthesized. The compounds described herein,and other related compounds having different substituents can besynthesized using techniques and materials known to those of skill inthe art, such as described, for example, in March, ADVANCED ORGANICCHEMISTRY 4th Ed., (Wiley 1992); Carey and Sundberg, ADVANCED ORGANICCHEMISTRY 4th Ed., Vols. A and B (Plenum 2000, 2001), and Green andWuts, PROTECTIVE GROUPS IN ORGANIC SYNTHESIS 3rd Ed., (Wiley 1999) (allof which are incorporated by reference in their entirety). Generalmethods for the preparation of the compounds as disclosed herein may bederived from known reactions in the field, and the reactions may bemodified by the use of appropriate reagents and conditions, as would berecognized by the skilled person, for the introduction of the variousmoieties found in the formulae as provided herein.

Additional biguanide synthesis methods and schemes for the compoundsdescribed herein can be found in U.S. application Ser. No. 12/593,479(published as U.S. 2010/0130498); U.S. application Ser. No. 12/593,398(published as U.S. 2010/0184796); U.S. Pat. No. 7,829,299; U.S.application Ser. No. 11/578,013 (published as U.S. 2010/0056621); U.S.Pat. No. 7,416,867; U.S. application Ser. No. 11/455,693 (published asU.S. 2007/0037212); U.S. application Ser. No. 13/059,730 (published asU.S. 2011/0143376), U.S. application Ser. No. 12/996,670 (published asU.S. 2011/0311991), U.S. Pat. No. 7,811,788; U.S. application Ser. No.11/182,942 (published as U.S. 2006/0019346); U.S. application Ser. No.12/993,542 (published as U.S. 2011/0086138), U.S. application Ser. No.12/373,235 (published as U.S. 2010/0055209); International ApplicationSer. No. PCT/IL2007/000454 (published as WO 2007/116404); U.S.application Ser. No. 10/472,056 (published as U.S. 2004/0138189); U.S.Pat. Nos. 5,891,919; 6,376,657; U.S. application Ser. No. 11/554,982(published as U.S. 2007/0104805); U.S. application Ser. No. 11/926,745(published as U.S. 2008/0108604); International Application Ser. No.PCT/CA2009/001688 (published as WO 2010/060198); U.S. application Ser.No. 12/735,557 (published as U.S. 2010/0330205); InternationalApplication Ser. No. PCT/CA2007/001066 (published as WO 2008/000063);U.S. application Ser. No. 11/438,204 (published as U.S. 2006/0269617);U.S. application Ser. No. 10/563,713 (published as U.S. 2006/0172020);U.S. application Ser. No. 10/902,352 (published as U.S. 2006/0024335);U.S. application Ser. No. 10/538,038 (published as U.S. 2006/0275765),U.S. application Ser. No. 11/555,617 (published as U.S. 2008/0187936);U.S. application Ser. No. 12/739,264 (published as U.S. 2010/0316736);U.S. application Ser. No. 12/215,609 (published as U.S. 2009/0042813);U.S. application Ser. No. 11/893,088 (published as U.S. 2008/0050499);U.S. Pat. No. 7,807,204; U.S. application Ser. No. 11/811,166 (publishedas U.S. 2008/0003268); U.S. Pat. No. 6,376,657; InternationalApplication Ser. No. PCT/US2011/041183 (published as WO 2011/163183);International Application Ser. No. PCT/EP2011/059814 (published as WO2011/157692); U.S. application Ser. No. 12/790,292 (published as U.S.2011/0293753); International Application Ser. No. PCT/JP2009/071700(published as WO 2010/076879); U.S. application Ser. No. 13/032,530(published as U.S. 2011/0217394); International Application Ser. No.PCT/EP2011/000110 (published as WO 2011/085979); InternationalApplication Ser. No. PCT/US2010/058467 (published as WO 2011/068814);U.S. application Ser. No. 13/060,996 (published as U.S. 2011/0152361);U.S. application Ser. No. 12/09,253 (published as U.S. 2011/0124609);U.S. application Ser. No. 12/687,962 (published as U.S. 2011/0119499);and International Application Ser. No. PCT/EP2010/004623 (published asWO 2011/012298); each of which are incorporated by reference in theirentirety.

Administration and Methods

The biguanide compounds of the disclosure, including analogs, salts,solvates, polymorphs, hydrates, N-oxides, and prodrugs of suchcompounds, may be administered to a subject in need thereof to treatvarious metabolic disorders, including obesity, dislipidemia or otherdisorders of lipid metabolism as well as hyperglycemic conditions andhistopathological diseases associated with hyperglycemia, including typeII diabetes. Particularly in view of the surprising and unexpecteddecoupling of systemic bioavailability and therapeutic efficacy achievedherein, and consequent improvement in toxicity and safety, the effectiveuse of such compounds for prophylaxis and prevention of such diseasesand disorders, as well as use for more general weight loss purposes, isalso explicitly contemplated herein.

In preferred embodiments, the compound is metformin. Prior formulationsof metformin are reported to have an average bioavailability of 30% to60% while many comparable small molecules have bioavailability ofgreater than 60%. See, e.g., Tucker et al., “Metformin kinetics inhealthy subjects and in patients with diabetes mellitus” Br. J. Clin.Pharmacol. 1981, 12(2) 235-246. Notably, metformin administrationincreases plasma concentrations of GLP-1 in normal, diabetic andDPP-IV-deficient rodents, as well as in humans with and without type IIdiabetes, but has been reported to do so indirectly and independent of adirect impact on intestinal L cells. Mulherin et al., supra.

As demonstrated herein, however, and contrary to the well-establishedconvention in the art, enteroendocrine activation by metformin may betriggered by luminal signals on the epithelial aspect of the gut, andtherefore increased systemic bioavailability of metformin is actuallyunnecessary after oral ingestion in order to stimulate the release ofgastrointestinal hormones such as GLP-1. Accordingly, the effectivetreatment of otherwise contraindicated patients is now made possible byadministering compositions comprising biguanide compounds (includinganalogs, salts, solvates, polymorphs, hydrates, N-oxides, and prodrugsthereof) adapted to minimize the systemic bioavailability of thecompound. In preferred embodiments, the subject compositions and methodsare formulated so as to minimize and preferably avoid an initial releasein the stomach and/or proximal small intestine (areas with the greatestabsorption) in order to reduce systemic bioavailability upon oraladministration.

Delivery to Specific Intestinal Locations

The embodiments described herein provide a treatment method comprisingadministering a delayed-release composition comprising a biguanidecompound (including any analogs, salts, solvates, polymorphs, hydrates,N-oxides, or prodrugs thereof) formulated to be delivered to one or morelocations of the small intestine and/or lower intestine, and preferablydistal small intestine, in order to minimize systemic bioavailability byavoiding absorption in the stomach and proximal small intestine andcorresponding rapid increase in C_(max).

The biguanide compounds are targeted beyond the stomach to one or moreregions of the small intestine, and are preferably targeted downstreamor distal of the duodenum. In preferred embodiments, the compounds aredelivered to the jejunum, ileum, caecum and colon, or a combinationthereof. In preferred embodiments, the compounds are delivered to thejejunum, ileum and caecum, or a combination thereof. In preferredembodiments, the compounds are preferentially targeted to the ileum. Inadditional embodiments, the compound is delivered downstream or distalof the jejunum, or solely to the lower intestine.

In yet other embodiments, the biguanide compound (including an analog,salt, solvate, polymorph, hydrate, N-oxide, or prodrug thereof) isdelivered to one or more regions of the upper intestine and one or moreregions of the lower intestine. For example, the compound can bedelivered to the duodenum and the colon. In another non-limitingexample, the compound can be delivered to the duodenum, jejunum, ileumand colon.

The administration of biguanides such as metformin to the preferredregions or locations of the intestine may be achieved by any knownmethod. In preferred embodiments, the biguanide compound is formulatedin a delayed-release composition for oral delivery that delivers thecompound to the targeted regions or locations of the intestine. Whendelivery of the biguanide compound is targeted to two or more regions ofthe gastrointestinal tract, the compound may be delivered in anyproportion and manner.

Minimizing Systemic Exposure

As described above, the methods disclosed herein minimize the systemicbioavailability of the biguanide compound in contraindicated patients.In some embodiments, the biguanide compounds have reduced averagesystemic bioavailability. Reduced average systemic bioavailabity, insome embodiments, is lower average systemic bioavailability as comparedto an immediate release or extended release formulation having anequivalent amount of the biguanide compound. In other embodiments,reduced average systemic bioavailability is when the average systemicbioavailability is less than 30%, less than 25%, less than 15%, lessthan 10% and less than 5% as compared to an immediate or extendedrelease formulation having an equivalent amount of the biguanidecompound. In certain instances, the average systemic bioavailability isless than 15%.

In some embodiments, the subject methods minimize the mean plasmaC_(max) and/or mean AUC levels of the biguanide compound incontraindicated patients. In some embodiments, the administrationmethods result in minimal plasma absorption, mean C_(max) and/or meanAUC levels of the biguanide compounds in the patient. It otherembodiments, the mean plasma C_(max), and/or mean AUC levels of thebiguanide compound are considered sub-therapeutic for the describedcompositions as compared to the reported C_(max) and/or AUC levels ofconventional immediate-release and extended-release formulations havingidentical amounts of metformin. For example, negligible orsub-therapeutic metformin plasma C_(max) and/or AUC levels include 75%,60%, 50%, 40% and 30% of reported C_(max) and/or AUC levels of knownmetformin formulations (e.g., GLUMETZA®, GLUCOPHAGE®, GLUCOPHAGE® XR,RIOMET®, FORTAMET®, OBIMET®, GLUFORMIN®, DIANBEN®, DIABEX®, DIAFORMIN®,Metformin IR®, Metformin SR®, and the like).

In specific embodiments, the inventive compositions and methods directedto metformin produce a C_(m)ax that is no more than 75% or 85%,preferably no more than 50% or 60%, more preferably no more than 25% or30% or 40% of the same dose of an immediate release metforminformulation (e.g. GLUCOPHAGE®) following oral ingestion. In otherembodiments, the inventive methods provide a C_(max) that is no morethan 3×, more preferably no more than 2.5× or 2×, still more preferablyno more than 1.8× or 1.5× the initial trough plasma concentration 10-12hours after the last oral ingestion of metformin. In other embodiments,the inventive compositions and methods provide a mean plasma AUC overthe dosing interval that is no more than 75% or 80%, preferably no morethan 50% or 60%, more preferably no more than 25%, 30% or 40% of thesame dose of an immediate release formulation (e.g. GLUCOPHAGE®)following oral ingestion.

Accordingly, in specific embodiments, administration of the subjectdelayed-release formulation minimizes the mean plasma AUC, the meanplasma C_(max) and/or the circulating plasma concentration of thebiguanide compound in contraindicated patients compared to an identicalprotocol administering an IR or XR formulation having the same amount ofthe biguanide compound. In one embodiment, the mean plasma AUC_(0-∞), ofthe biguanide compound resulting from administration is less than about15,000 ng*h/mL or 14,000 ng*h/mL, preferably less than about 12,000ng*h/mL, 11,000 ng*h/mL or 10,000 ng*h/mL, more preferably less thanabout 9,000 ng*h/mL, 8,000 ng*h/mL or 7,000 ng*h/mL. In one embodiment,the resulting mean plasma C_(max) of the biguanide compound is less thanabout 1000 ng/mL, preferably less than about 900 ng/mL or 800 ng/mL,more preferably less than about 700 ng/mL, 600 ng/mL or 500 ng/mL. Inone embodiment, the resulting circulating plasma concentration of thebiguanide compound is below about 5 μg/ml or 4 μg/ml, preferably belowabout 3 μg/ml or 2.5 μg/ml, more preferably below about 2 μg/ml, 1μg/ml, 0.5 μg/ml, or 0.25 μg/ml in the patient. In preferredembodiments, the biguanide compound is metformin, the IR composition isGlucophage® and the XR composition is Glucophage® XR.

Formulations

To limit its systemic bioavailability, the compositions comprising thebiguanide compound are adapted for delayed release so as to minimizeplasma absorption. The delivery of biguanide compounds such as metforminto the enteroendocrine cells is via any known method including, e.g.,oral, rectal, nasogastric tube, parenterally injection such asintraluminal intestinal injection. In preferred embodiments, oral dosageforms are administered. Oral delivery of biguanide compounds isdescribed in the delayed release formulations section and include timedrelease systems, enteric coatings and pH dependent systems, and thelike. In some embodiments, the compositions comprising the compoundsdescribed herein utilize a multicomponent system where the biguanidecompound is delivered to several places in the gastrointestinal tractsuch as the duodenum, jejunum, ileum, lower intestine or combinationsthereof following administration. For example, a delayed-releaseformulation comprising the biguanide compound can deliver to the lowerintestine by use of timed or delayed (enteric) release components.Multicomponent systems of such compounds can be in unitary dosage formssuch as bi- or tri- or multiple-layer tablets or multi-particulate formssuch as encapsulated micro-tablets, granules or as separate dosageforms, e.g., separate tablets taken together or at a periodic interval.

In some embodiments, the delayed-release formulation releases thebiguanide compound after onset of a desired pH, due to the entericcoating. pHs contemplated include about pH 5.0 or about pH 5.5, morepreferably about pH 6.0, about pH 6.5 and about pH 7.0. After onset of adesired pH, the compound begins release. Such compositions may releasethe biguanide compound in about 15 minutes, about 20 minutes, about 25minutes or about 30 minutes after the onset of the desired pH, and/ormay have timed, extended or slow release aspects that release thebiguanide compound over the course of a longer time period such as about1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours,about 6 hours, about 7 hours or about 8 hours. Exemplary two componentdelivery system can be, in some embodiments, a bilayer tablet. Three,four and additional components are contemplated within the embodiments.

For delayed-release formulations comprising the biguanide compound,dosages of the compound can range from about 1 mg to about 2000 mg,about 10 mg to about 1500 mg, about 50 mg to about 1000 mg or about 100mg or about 500 mg per day. In some instances, the dosage of thecompound is about 2000 mg, about 1500 about 1000 mg, about 800 mg, about600 mg, about 500 mg, about 400 mg, about 300 mg, about 250 mg, about200 mg, about 150 mg, about 100 mg, about 75 mg, about 50 mg, about 25mg, about 10 mg or about 1 mg per day. In some embodiments, the dosageof the compound is less than 400 mg. In some embodiments, the dosage ofthe compound is 250 mg.

Salts of biguanide compound include, but are not limited to,hydrochloride, phosphate, sulfate, hydrobromide, salicylate, maleate,benzoate, succinnate, ethanesulfonate, fumarate, glycolate, pamoate,oratate, acetate, isobutyrate, acetylsalicylate, nicotinic acid,adamantoate, zinc chlorophylin, carboxylic acid, benzoic acid,dichloroacetic acid, theophylin-7-acetate, clofibrate, tartate, oxalate,tannate and hydroxyl acid salts. In preferred embodiment, the salt ismetformin hydrochloride.

The biguanide compounds of the subject invention can be advantageouslyadministered or combined with additional therapeutic agents, such asanti-obesity and/or anti-diabetic agents described herein. Notableagents for combinations with the metformin compositions described hereininclude DPP-IV inhibitors (e.g., sitagliptin, saxagliptin, bcrbcrinc,vildagliptin, linagliptin, alogliptin, and the like), SGLT-2 and/orSGLT-1 inhibitors (e.g., dapafloglizin, canafloglizin, LX4211), agonistsof GPR40, GPR120, GPR119, GPR41, GPR43, etc., thiazolidinediones (e.g.,pioglitazone, rivoglitazone, rosiglitazone, troglitazone, and the like),sulfonylureas (e.g., glipzide, glibenclamide (glyburide), gliquidone,glyclopyramide, glimepiride, gliclazide, acetohexamide, carbutamide,chlorpropamide, tolbutamide, tolazamide, and the like), Dual PPARagonists (e.g., aleglitazar, muraglitazar, tesaglitazar, and the like),lipid-lowering agents (e.g., statins), and anti-hypertensive agents.

Formulations for the compositions provided herein include those suitablefor oral or rectal administration, and administration although the mostsuitable route can depend upon for example the condition and disorder ofthe recipient. The formulations can conveniently be presented in unitdosage form and can be prepared by any of the methods well known in theart of pharmacy. All methods include the step of bringing intoassociation the active ingredient with the carrier which constitutes oneor more accessory ingredients.

Formulations suitable for oral administration can be presented asdiscrete units such as capsules, cachets or tablets each containing apredetermined amount of the active ingredient; as a powder or granules;as a solution or a suspension in an aqueous liquid or a non-aqueousliquid; or as an oil-in-water liquid emulsion or a water-in-oil liquidemulsion.

Composition preparations which can be used orally include tablets,push-fit capsules made of gelatin, as well as soft, sealed capsules madeof gelatin and a plasticizer, such as glycerol or sorbitol. Tablets canbe made by compression or molding, optionally with one or more accessoryingredients. Compressed tablets can be prepared by compressing in asuitable machine the active ingredient in a free-flowing form such as apowder or granules, optionally mixed with binders (e.g., povidone,gelatin, hydroxypropylmethyl cellulose), inert diluents, preservative,disintegrant (e.g., sodium starch glycolate, cross-linked povidone,cross-linked sodium carboxymethyl cellulose) or lubricating, surfaceactive or dispersing agents. Molded tablets can be made by molding in asuitable machine a mixture of the powdered compound moistened with aninert liquid diluent. The tablets can optionally be coated or scored andcan be formulated so as to provide slow or controlled release of theactive ingredient therein. Tablets can optionally be provided with anenteric coating, to provide release in parts of the gut other than thestomach. All formulations for oral administration should be in dosagessuitable for such administration. The push-fit capsules can contain theactive ingredients in admixture with filler such as lactose, binderssuch as starches, and/or lubricants such as talc or magnesium stearateand, optionally, stabilizers. In soft capsules, the active compounds canbe dissolved or suspended in suitable liquids, such as fatty oils,liquid paraffin, or liquid polyethylene glycols. In addition,stabilizers can be added. Dragee cores are provided with suitablecoatings. For this purpose, concentrated sugar solutions can be used,which can optionally contain gum arabic, talc, polyvinyl pyrrolidone,carbopol gel, polyethylene glycol, and/or titanium dioxide, lacquersolutions, and suitable organic solvents or solvent mixtures. Dyestuffsor pigments can be added to the tablets or Dragee coatings foridentification or to characterize different combinations of activecompound doses.

It should be understood that in addition to the ingredients particularlymentioned above, the compounds and compositions described herein caninclude other agents conventional in the art having regard to the typeof formulation in question, for example those suitable for oraladministration can include flavoring agents.

The compositions described herein can also contain the biguanidecompound in a form suitable for oral use, for example, as tablets,troches, lozenges, aqueous or oily suspensions, dispersible powders orgranules, emulsions, hard or soft capsules, or syrups or elixirs.Compositions intended for oral use can be prepared according to anymethod known to the art for the manufacture of pharmaceuticalcompositions, and such compositions can contain one or more agentsselected from, by way of non-limiting example, sweetening agents,flavoring agents, coloring agents and preserving agents in order toprovide pharmaceutically elegant and palatable preparations.

Delayed Release Formulations

Many strategies can be pursued to obtain delayed release in which thelocation of the release is controlled so as to minimize systemicabsorption. For example, delayed release can be obtained by theappropriate selection of formulation parameters and ingredients (e.g.,appropriate controlled release compositions and coatings). Examplesinclude single or multiple unit tablet or capsule compositions, oilsolutions, suspensions, emulsions, microcapsules, microspheres,nanoparticles and liposomes. The release mechanism can be controlledsuch that the biguanide compounds are released at period intervals orthe location of the release is controlled, the release of combinedagents can be simultaneous, or a delayed release of the biguanidecompound in a combination can be affected when the early release ofanother combined therapeutic one is preferred over the other. Differentdelivery systems described herein can also be combined to release at anonset of multiple period intervals (e.g., about 30 minutes, about 120minutes, about 180 minutes and about 240 minutes after oraladministration) or at different locations (e.g., release in the lowerintestine, upper intestine, the jejunum, ileum, caecum, colon, and/orrectum) or a combination thereof. For example, a pH dependent system canbe combined with a timed release system or any other system describedherein to achieve a desired release profile.

In certain embodiments, the biguanide compounds are provided in the formof a delayed release formulation coupled with an extended releasecomponent of the biguanide compound and/or an additional therapeuticagent in a unitary dosage form. The extended release component can beformulated by any known method such as a layer that envelops a portionof the delayed release component or the like. Exemplary ratios ofextended release of an additional therapeutic agent to delayed releaseof a biguanide compound are about 10% XR to about 90% DR, about 15% XRto about 85% DR, about 20% XR to about 80% DR, about 25% XR to about 75%DR, about 30% XR to about 70% DR, about 35% XR to about 65% DR, about40% XR to about 60% DR, about 45% XR to about 55% DR, or about 50% XR toabout 50% DR. In certain embodiments, the extended release of an activeagent to modified release of an active agent is about 25% XR to about75% DR. In certain embodiments, the extended release of an active agentto modified release of an active agent is about 20% XR to about 80% DR.Unitary dosage forms with an XR and DR component include any knownformulation including bilayer tablets, coated pellets, and the like.

In certain embodiments, the biguanide compounds are provided in the formof a delayed release formulation coupled with an immediate releasecomponent of an additional therapeutic agent in a unitary dosage form.The immediate release component can be formulated by any known methodsuch as a layer that envelops the delayed release component or the like.Exemplary ratios of immediate release of an additional therapeutic agentto delayed release of a biguanide compound are about 10% IR to about 90%DR, about 15% IR to about 85% DR, about 20% IR to about 80% DR, about25% IR to about 75% DR, about 30% IR to about 70% DR, about 35% IR toabout 65% DR, about 40% IR to about 60% DR, about 45% IR to about 55%DR, or about 50% IR to about 50% DR. In certain embodiments, theimmediate release of an active agent to delayed release of an activeagent is about 25% IR to about 75% DR. In certain embodiments, theimmediate release of an active agent to delayed release of an activeagent is about 20% IR to about 80% DR. Unitary dosage forms with an IRand DR component include any known formulation including bilayertablets, coated pellets, and the like.

Timed Release Systems

In one embodiment, the delayed-release mechanism is a “timed” ortemporal release (“TR”) system that releases an active agent, forexample a biguanide compound, at certain timepoints subsequent toadministration. Timed release systems are well known in the art andsuitable timed release systems can include any known excipient and/orcoating. For example, excipients in a matrix, layer or coating can delayrelease of an active agent by slowing diffusion of the active agent intoan environment. Suitable timed release excipients include but are notlimited to, acacia (gum arabic), agar, aluminum magnesium silicate,alginates (sodium alginate), sodium stearate, bladderwrack, bentonite,carbomer, carrageenan, Carbopol, cellulose, microcrystalline cellulose,ceratonia, chondrus, dextrose, furcellaran, gelatin, Ghatti gum, guargum, galactomannan, hectorite, lactose, sucrose, maltodextrin, mannitol,sorbitol, honey, maize starch, wheat starch, rice starch, potato starch,gelatin, sterculia gum, xanthum gum, Glyceryl behenate (e.g., Compritol888 ato), Gylceryl distearate (e.g. Precirol ato 5), polyethylene glycol(e.g., PEG 200-4500), polyethylene oxide, adipic acid, gum tragacanth,ethyl cellulose (e.g., ethyl cellulose 100), ethylhydroxyethylcellulose, ethylmethyl cellulose, methyl cellulose, hydroxyethylcellulose, hydroxyethylmethyl cellulose (e.g., K1OOLV, K4M, K15M),hydroxypropyl cellulose, poly(hydroxyethyl methacrylate), celluloseacetate (e.g. cellulose acetate CA-398-10 NF), cellulose acetatephthalate, cellulose acetate propionate, cellulose acetate butyrate,hydroxypropyl methyl cellulose acetate succinate, hydroxypropyl methylcellulose phthalate, cellulose butyrate, cellulose nitrate,oxypolygelatin, pectin, polygeline, povidone, propylene carbonate,polyandrides, methyl vinyl ether/maleic anhydride copolymer (PVM/MA),poly(methoxyethyl methacrylate), poly(methoxyethoxyethyl methacrylate),hydroxypropyl cellulose, hydroxypropylmethyl cellulose, sodiumcarboxymethyl-cellulose (CMC), silicon dioxide, vinyl polymers, e.g.polyvinyl pyrrolidones(PVP: povidone), polyvinyl acetates, or polyvinylacetate phthalates and mixtures, Kollidon SR, acryl derivatives (e.g.polyacrylates, e.g. cross-linked polyacrylates, methycrylic acidcopolymers), Splenda® (dextrose, maltodextrin and sucralose) orcombinations thereof. The timed release excipient may be in a matrixwith active agent, in another compartment or layer of the formulation,as part of the coating, or any combination thereof. Varying amounts ofone or more timed release excipients may be used to achieve a designatedrelease time.

One non-limiting example includes formulations of the TIMERx® system.This controlled release formulation system provides for altered temporalrelease (SyncroDose™) as well as biphasic release (Geminex®). (See, forexample, Staniforth & Baichwal, TIMERx®: novel polysaccharide compositesfor controlled/programmed release of active ingredients in thegastrointestinal tract, Expert Opin. Drug Deliv., 2(3): 587-89 (2005)).Using formulations such as these for the invention described herein,compositions can be created which target the upper gastrointestinaltract, the lower gastrointestinal tract, or both, in addition totemporally controlling the release of such compounds in any of theselocations.

In some embodiments, the timed release systems are formulated to releasethe compound at an onset of about 5 minutes, about 10 minutes, about 20minutes, about 30 minutes, about 40 minutes, about 50 minutes, about 60minutes, about 70 minutes, about 80 minutes, about 90 minutes, about 100minutes, about 110 minutes, about 120 minutes, about 130 minutes, about140 minutes, about 150 minutes, about 160 minutes, about 170 minutes,about 180 minutes, about 190 minutes, about 200 minutes, about 210minutes, about 220 minutes, about 230 minutes, about 240 minutes, about250 minutes, about 260 minutes, about 270 minutes, about 280 minutes,about 290 minutes, about 300 minutes, about 310 minutes, about 320minutes, about 330 minutes, about 340 minutes, about 350 minutes, about360 minutes, about 370 minutes, about 380 minutes, about 390 minutes,about 400, about 400, about 410, or about 420 minutes subsequent toadministration. In embodiments with multiple releases, timed releasesystems are formulated to release at more than one time point. Incertain embodiments, the timed release systems are formulated to releaseat an onset of about 10 minutes, about 30 minutes, about 120 minutes,about 180 minutes and about 240 minutes after administration. In certainembodiments the timed release systems are formulated to release at anonset of about 5 to about 45 minutes, about 105 to about 135 minutes,about 165 to about 195 minutes, about 225 to about 255 minutes or acombination of times thereof following administration to a patient.

Enteric Coatings and pH Dependent Systems

The formulation may also be coated with an enteric coating, whichprotects an active agent, for example a biguanide compound, fromdegradation in an acidic environment, such as the stomach, and allows adelayed release into a target area, for example the ileum, for uptake.

The enteric coating may be, as a non-limiting example, wax or wax likesubstance, such as carnauba wax, fatty alcohols, hydrogenated vegetableoils, zein, shellac, sucrose, Arabic gum, gelatin, dextrin, psylliumhusk powder, polymethacrylates, anionic polymethacrylates, mixtures ofpoly(methacrylic acid, methyl methacrylate), polymers or copolymersderived from acrylic and/or methacrylic acid esters, cellulose acetatephthalate, cellulose acetate trimelliate, hydroxypropyl methylcellulosephthalate (HPMCP), cellulose propionate phthalate, cellulose acetatemaleate, polyvinyl alcohol phthalate, hydroxypropyl methylcelluloseacetate succinate (HPMCAS), hydroxypropyl methylcellulosehexahydrophthalate, polyvinyl acetate phthalate, mixtures ofpoly(methacrylic acid, ethyl acrylate), ethylcellulose, methylcellulose,propylcellulose, chitosan succinate, chitosan succinate, polyvinylacetate phthalate (PVAP), polyvinyl acetate polymers carboxymethylethylcellulose and compatible mixtures thereof. In addition, an inactiveintermediate film may be provided between the biguanide compound, andthe enteric coating to prevent interaction of the biguanide compoundwith the enteric coating.

In one non-limiting example, silicone microspheres for pH-controlledgastrointestinal drug delivery have been described by Carelli et al.,Int. J. Pharmaceutics 179: 73-83, 1999. The microspheres arepH-sensitive semi-interpenetrating polymer hydrogels made of varyingproportions of poly(methacrylic acid-co-methylmethacrylate) (EUDRAGIT®L100 or EUDRAGIT® S100) and crosslinked polyethylene glycol 8000 thatare encapsulated into silicone microspheres. The EUDRAGIT® series ofmethacrylic acid copolymers are commercially available from EvonikIndustries in Darmstadt, Germany.

The enteric coatings can be formulated to release a biguanide compoundat a desired pH using combinations of enteric polymers. It is well-knownthat different locations of the gastrointestinal system have specificpHs. For example, the duodenum may correspond to a pH 5.5 environmentand the jejunum may correspond to pH 6.0 environment. In preferredembodiments, the enteric coatings are formulated to release the compoundat an onset of a desired pH, e.g., in the distal small intestine andlower intestine, i.e., at about pH 6, about pH 6.5, or about pH 7. Inembodiments with multiple releases, the enteric coatings are formulatedto release at an onset of two or more pH values. In certain embodiments,the enteric coatings are formulated to release at an onset of pH 6.0,6.5 and 7.0. In certain embodiments, the enteric coatings are formulatedto release at an onset of pH 6.5 and 7.0. In certain embodiments, theenteric coatings are formulated to release at the jejunum, ileum, andlower intestine. In yet other embodiments, the enteric coatings are usedin combination with other release systems such as a timed releasesystem.

In yet other embodiments, the enteric coatings are used in combinationwith an immediate release/extended release unitary dosage form. Forexample, a unitary dosage form, such as a bilayer tablet with a 20%IR/80% MR component of the biguanide compound can be coated with anenteric coating that releases at pH, e.g., 5.5, 6.0, 6.5, 7.0 so thatthe release is delayed until the dosage form reaches a pH of e.g., 5.5,6.0, 6.5, 7.0 thereby releasing the IR component immediately and the MRcomponent according to its MR release properties. In certain instances,the enteric coatings are used in combination with an immediaterelease/timed release unitary dosage forms.

The microcapsules gastroretentive systems described in U.S. Pat. Nos.6,022,562, 5,846,566 and 5,603,957, can be used in the delayed releasedelivery methods described herein. Microparticles of an active agent ordrug are coated by spraying with a material consisting of a mixture of afilm-forming polymer derivative, a hydrophobic plasticizer, a functionalagent and a nitrogen-containing polymer. The resulting microcapsules areless than or equal to 1000 microns (gm) in size, and in certain casessuch microcapsules are between 100 and 500 microns. These microcapsulesremain in the small intestine for at least 5 hours.

Film-forming polymer derivatives used in such microcapsules include, butare not limited to, ethylcellulose, cellulose acetate, andnon-hydrosoluble cellulose derivates. The nitrogen-containing polymersinclude, but are not limited to, polyacrylamide, poly-N-vinylamide,poly-N-vinyl-lactam and polyvinylpyrrolidone. The plasticizer used insuch microcapsule include, but are not limited to, glycerol esters,phthalates, citrates, sebacates, cetylalcohol esters, castor oil andcutin. The surface-active and/or lubricating agent used in suchmicrocapsule include, but are not limited to, anionic surfactants, suchas by way of example the alkali metal or alkaline-earth metal salts offatty acids, stearic acid and/or oleic acid, nonionic surfactants, suchas by way of example, polyoxyethylenated esters of sorbitan and/orpolyoxyethylenated esters of sorbitan and/or polyoxyethylenatedderivatives of castor oil; and/or lubricants such as stearates, such asby way of example, calcium, magnesium, aluminum stearate, zinc stearate,stearylfumarate, sodium stearylfimarate, and glyceryl behenate.

One non-limiting example of a lower GI delivery formulation comprises atablet for lower GI delivery. The inner composition of the tabletcomprises about 0.01% weight to about 10.0% by weight of a suitableactive ingredient; about 50% by weight to about 98% by weight of ahydrocolloid gum obtainable from higher plants; and about 2% by weightto about 50% by weight of a pharmaceutically acceptable excipient suchas a binder. Other optional materials may be present that will assist inestablishing the desired characteristics of the pharmaceuticalcomposition. These include materials that may enhance absorption of theactive ingredient in the lower GI, may protect the active ingredientagainst degradation, may prevent dissolution, and the like. Optionallysurrounding the inner composition of the tablet is a coating that ispreferably of enteric polymeric material.

The formulation is designed to take advantage of (1) the protectivecharacteristics of the hydrocolloid obtainable from higher plants in theupper GT and (2) the disintegrative characteristics of the hydrocolloidin the lower GI. Thus, the inner composition of the tablet may be one ofseveral designs: (a) it may be a matrix of a therapeutically effectiveamount of the active ingredient uniformly dispersed throughout incombination with a high percentage of the hydrocolloid and a generallylesser amount of other excipients; (b) it may have a core, in which theactive ingredient is concentrated, surrounded by a layer of materialthat is free of the active ingredient and that has a high percentage ofthe hydrocolloid and a generally lesser amount of other excipients; (c)it may have a concentration gradient of the active ingredient such thatthere is a greater amount in the core of the tablet with lesser amountsin multiple layers surrounding the core and very little or no activeingredient in the outer layer. Whether the design of the tablet is thatof (a), (b) or (c) above, the specificity for regional delivery to thelower GI is enhanced by enterically coating the tablet with anappropriate enteric coating material.

Suitable hydrocolloids are well known in the art. See for example “TheChemistry of Plant Gums and Mucilages” by Smith and Montgomery from theA.C.S. Monograph series, #141, 1959, Reinhold Publishing Co. and theEighteenth Edition of The Merck Index. In general, the amount of thehydrocolloid that will be used is an amount that allows the compositionto traverse the upper GI tract without significant disintegration andwithout releasing significant amounts of active ingredient in the upperGI tract, i.e. to provide a delayed-release profile. Generally, thatamount of hydrocolloid will be more than about 50% but less than about98%. Depending on individual variability, whether a patient has eaten orhas fasted, and other factors, a tablet will traverse the stomach andupper intestinal tract in about 3 to 6 hours. During this time, littleactive ingredient (less than 20%, preferably less than 10%) is releasedfrom the tablet of this invention. Once the tablet reaches the lower GI,the release of the active ingredient is triggered by enzymaticdegradation of the galactomannan gum.

Modified Release Formulations

In additional embodiment, the methods and compositions directed tobiguanide compound delivery may further employ controlled, sustained, orextended release formulations known collectively as “modified release”formulations. Compositions can be administered by modified releasesystems or by delivery devices that are well known to those of ordinaryskill in the art. Examples include, but are not limited to, thosedescribed in U.S. Pat. Nos. 3,845,770; 3,916,899; 3,536,809; 3,598,123;4,008,719; 5,674,533; 5,059,595; 5,591,767; 5,120,548; 5,073,543;5,639,476; 5,354,556; and 5,733,566. Such dosage forms can be used toprovide modified release of one or more active ingredients using, forexample, hydropropylmethyl cellulose, other polymer matrices, gels,permeable membranes, osmotic systems, multilayer coatings,microparticles, liposomes, microspheres, or a combination thereof toprovide the desired release profile in varying proportions. Suitablemodified release formulations known to those of ordinary skill in theart, including those described herein, can be readily selected for usewith the active ingredients of the invention. The invention thusencompasses single unit dosage forms suitable for oral administrationsuch as, but not limited to, tablets, capsules, gelcaps, and capletsthat are further adapted for modified release.

In some embodiments, the modified release systems are formulated torelease the compound at a duration of about 30 minutes, about 40minutes, about 50 minutes, about 60 minutes, about 70 minutes, about 80minutes, about 90 minutes, about 100 minutes, about 110 minutes, about120 minutes, about 130 minutes, about 140 minutes, about 150 minutes,about 160 minutes, about 170 minutes, about 180 minutes, about 190minutes, about 200 minutes, about 210 minutes, about 220 minutes, about230 minutes, about 240 minutes, about 250 minutes, about 260 minutes,about 270 minutes, about 280 minutes, about 290 minutes, about 300minutes, about 310 minutes, about 320 minutes, about 330 minutes, about340 minutes, about 350 minutes, about 360 minutes, about 370 minutes,about 380 minutes, about 390 minutes, about 400, about 400, about 410,or about 420 minutes subsequent to onset of the release. In embodimentswith multiple releases, modified release systems are formulated torelease at more than one durations of time at different time points.

In one non-limiting example, chitosan and mixtures of chitosan withcarboxymethylcellulose sodium (CMC-Na) have been used as vehicles forthe sustained release of active ingredients, as described by Inouye etal., Drug Design and Delivery 1: 297-305, 1987. Mixtures of thesecompounds and agents of the combinations of the invention, whencompressed under 200 kg/cm2, form a tablet from which the active agentis slowly released upon administration to a patient. The release profilecan be changed by varying the ratios of chitosan, CMC-Na, and activeagent(s). The tablets can also contain other additives, includinglactose, CaHPO4 dihydrate, sucrose, crystalline cellulose, orcroscarmellose sodium.

In another non-limiting example, Baichwal, in U.S. Pat. No. 6,245,356,describes sustained release oral, solid dosage forms that includeagglomerated particles of a therapeutically active medicament inamorphous form, a gelling agent, an ionizable gel strength enhancingagent and an inert diluent. The gelling agent can be a mixture of axanthan gum and a locust bean gum capable of cross-linking with thexanthan gum when the gums are exposed to an environmental fluid.Preferably, the ionizable gel enhancing agent acts to enhance thestrength of cross-linking between the xanthan gum and the locust beangum and thereby prolonging the release of the medicament component ofthe formulation. In addition to xanthan gum and locust bean gum,acceptable gelling agents that may also be used include those gellingagents well known in the art. Examples include naturally occurring ormodified naturally occurring gums such as alginates, carrageenan,pectin, guar gum, modified starch, hydroxypropylmethylcellulose,methylcellulose, and other cellulosic materials or polymers, such as,for example, sodium carboxymethylcellulose and hydroxypropyl cellulose,and mixtures of the foregoing.

In another non-limiting formulation useful for the combinations of theinvention, Baichwal and Staniforth in U.S. Pat. No. 5,135,757 describe afree-flowing slow release granulation for use as a pharmaceuticalexcipient that includes from about 20 to about 70 percent or more byweight of a hydrophilic material that includes a heteropolysaccharide(such as, for example, xanthan gum or a derivative thereof) and apolysaccharide material capable of cross-linking theheteropolysaccharide (such as, for example, galactomannans, and mostpreferably locust bean gum) in the presence of aqueous solutions, andfrom about 30 to about 80 percent by weight of an inertpharmaceutical-filler (such as, for example, lactose, dextrose, sucrose,sorbitol, xylitol, fructose or mixtures thereof). After mixing theexcipient with a tricyclic compound/corticosteroid combination, orcombination agent, of the invention, the mixture is directly compressedinto solid dosage forms such as tablets. The tablets thus formed slowlyrelease the medicament when ingested and exposed to gastric fluids. Byvarying the amount of excipient relative to the medicament, a slowrelease profile can be attained.

Slow-release formulations can also include a coating which is notreadily water-soluble but which is slowly attacked and removed by water,or through which water can slowly permeate. Thus, for example, thecombinations of the invention can be spray-coated with a solution of abinder under continuously fluidizing conditions, such as describe byKitamori et al., U.S. Pat. No. 4,036,948. Examples of water-solublebinders include pregelatinized starch (e.g., pregelatinized corn starch,pregelatinized white potato starch), pregelatinized modified starch,water-soluble celluloses (e.g. hydroxypropyl-cellulose,hydroxymethyl-cellulose, hydroxypropylmethyl-cellulose,carboxymethyl-cellulose), polyvinylpyrrolidone, polyvinyl alcohol,dextrin, gum arabicum and gelatin, organic solvent-soluble binders, suchas cellulose derivatives (e.g., cellulose acetate phthalate,hydroxypropylmethyl-cellulose phthalate, ethylcellulose).

In another non-limiting example, Villa et al., in U.S. Pat. No.6,773,720, describes a modified-release system containing an innerlipophilic matrix where an active ingredient is inglobated and an outerhydrophilic matrix in which the lipophilic matrix is dispersed. Anactive ingredient, such as a biguanide or related heterocyclic compound,is first inglobated in a low melting lipophilic excipient or mixture ofexcipients while heating to soften and/or melt the excipient itself,which thereby incorporates the active ingredient by simple dispersion.After cooling at room temperature, an inert matrix forms, which can bereduced in size to obtain matrix granules containing the activeingredient particles. The inert matrix granules are subsequently mixedtogether with one or more hydrophilic water-swellable excipients. Inthis respect, when the composition is contacted with biological fluids,a high viscosity swollen layer is formed, which coordinates the solventmolecules and acts as a barrier to penetration of the aqueous fluiditself inside the new structure. Said barrier antagonizes the staring“burst effect” caused by dissolution of the active ingredient inglobatedinside the inert matrix, which is in its turn inside the hydrophilicmatrix. One commercially available system of this type is from CosmoTechnologies Limited (Italy) under the trade name MMX® technology. Thelipophilic/hydrophilic matrices can be further enterically coated for pHspecific delivery.

Formulations for upper intestinal delivery, lower intestinal delivery orboth are known in the art. Targeting of active ingredients to variousregions of the gut is described, e.g., in The Encyclopedia ofPharmaceutical Technology, by James Swarbrick and James Boylan, InformaHealth Care, 1999, at pp. 287-308. Any suitable formulation forgastrointestinal delivery for site-specific delivery and/or specifictemporal delivery (i.e. delayed, controlled, extended, or sustainedrelease) can be used with the invention and is contemplated herein.

Any of the delivery systems described herein may be used in combinationwith others to achieve multiple releases and/or specific releaseprofiles. In some embodiments, the biguanide compound is in aformulation that achieves multiple releases in gastrointestinallocations following administration. In certain embodiments, thebiguanide compound is in a multiple release formulation that releases atan onset of about 10 minutes, about 30 minutes, about 120 minutes, about180 minutes, about 240 minutes, or combinations thereof followingadministration. In certain embodiments, the biguanide compound is in amultiple release formulation that releases at an onset of about 5 toabout 45 minutes, about 105 to about 135 minutes, about 165 to about 195minutes, about 225 to about 255 minutes, or combinations thereoffollowing administration.

In certain embodiments, the biguanide compound is in a multiple releaseformulation that releases in the duodenum, jejunum, ileum, lowerintestine or combinations thereof following administration. In yet otherembodiments, the biguanide compound is in a multiple release formulationthat releases at an onset of about pH 5.5, about pH 6.0, at about pH6.5, about pH 7.0, or combinations thereof following administration. Inyet other embodiments, the biguanide compound is in a multiple releaseformulation that releases in ranges at about pH 5.0 to about pH 6.0,about pH 6.0 to about pH 7.0, about pH 7.0 to about pH 8.0, orcombinations thereof following administration. In yet other embodiments,the biguanide compound is in a multiple release formulation thatreleases a fraction or portion of the biguanide as an immediate releasewith the rest of the compound released in a delayed manner as describedherein.

Oral Dosage Forms

Oral dosage forms suitable for use in the subject compositions andmethods include tablets, hard capsules, push-fit capsules made ofgelatin, as well as soft, sealed capsules made of gelatin and aplasticizer, such as glycerol or sorbitol, as well as troches, lozenges,aqueous or oily suspensions, dispersible powders or granules, emulsions,syrups or elixirs. Suitable oral dosage forms can be prepared accordingto any method known to the art for the manufacture of pharmaceuticalcompositions, and such compositions can contain one or more agentsselected from, by way of non-limiting example, sweetening agents,flavoring agents, coloring agents and preserving agents in order toprovide pharmaceutically elegant and palatable preparations.

Tablets contain the active ingredient in admixture with pharmaceuticallyacceptable excipients which are suitable for the manufacture of tablets.These excipients can be, for example, inert diluents, such as calciumcarbonate, sodium carbonate, lactose, calcium phosphate or sodiumphosphate; granulating and disintegrating agents, such asmicrocrystalline cellulose, sodium crosscarmellose, corn starch, oralginic acid; binding agents, for example starch, gelatin,polyvinyl-pyrrolidone or acacia, and lubricating agents, for example,magnesium stearate, stearic acid or talc. Tablets can be made bycompression or molding, optionally with one or more accessoryingredients. Compressed tablets can be prepared by compressing in asuitable machine the active ingredient in a free-flowing form such as apowder or granules, optionally mixed with binders (e.g., povidone,gelatin, hydroxypropylmethyl cellulose), inert diluents, preservatives,disintegrants (e.g., sodium starch glycolate, cross-linked povidone,cross-linked sodium carboxymethyl cellulose) or lubricating, surfaceactive or dispersing agents. Molded tablets can be made by molding in asuitable machine a mixture of the powdered compound moistened with aninert liquid diluent. The tablets are coated by known techniques todelay disintegration and absorption in the gastrointestinal tract andthereby minimize systemic bioavailability as described more fullyherein.

Formulations for oral use can also be presented as hard gelatin capsuleswherein the active ingredient is mixed with an inert solid diluent, forexample, calcium carbonate, calcium phosphate or kaolin, or as softgelatin capsules wherein the active ingredient is mixed with watersoluble carrier such as polyethyleneglycol or an oil medium, for examplepeanut oil, liquid paraffin, or olive oil. Alternatively, push-fitcapsules can contain the active ingredients in admixture with fillersuch as lactose, binders such as starches, and/or lubricants such astalc or magnesium stearate and, optionally, stabilizers. In softcapsules, the active compounds can be dissolved or suspended in suitableliquids, such as fatty oils, liquid paraffin, or liquid polyethyleneglycols. In addition, stabilizers can be added. Dragee cores areprovided with suitable coatings. For this purpose, concentrated sugarsolutions can be used, which can optionally contain gum arabic, talc,polyvinyl pyrrolidone, carbopol gel, polyethylene glycol, and/ortitanium dioxide, lacquer solutions, and suitable organic solvents orsolvent mixtures. Dyestuffs or pigments can be added to the tablets orDragee coatings for identification or to characterize differentcombinations of active compound doses.

It should be understood that in addition to the ingredients particularlymentioned above, the compounds and compositions described herein caninclude other agents conventional in the art having regard to the typeof formulation in question, for example those suitable for oraladministration can include flavoring agents.

In various embodiments, the compositions provided herein are in liquidform. Liquid forms include, by way of non-limiting example, neatliquids, solutions, suspensions, dispersions, colloids, foams and thelike. In certain instances, liquid forms contain also a nutritionalcomponent or base (e.g., derived from milk, yogurt, shake, or juice). Insome aspects, the compound are micronized or as nanoparticles in theliquid form. In certain instances, the compounds may be coated to maskthe tastant properties. In other instances, the compounds are coated tomodify delivery to the intestine and colon.

Aqueous solutions or suspensions contain the active ingredient(s) inadmixture with excipients suitable for the manufacture of aqueoussuspensions. Such excipients are suspending agents, for example sodiumcarboxymethylcellulose, methylcellulose, hydroxypropylmethyl-cellulose,sodium alginate, polyvinyl-pyrrolidone, gum tragacanth and gum acacia;dispersing or wetting agents can be a naturally-occurring phosphatide,for example lecithin, or condensation products of an alkylene oxide withfatty acids, for example polyoxyethylene stearate, or condensationproducts of ethylene oxide with long chain aliphatic alcohols, forexample heptadecaethylene-oxycetanol, or condensation products ofethylene oxide with partial esters derived from fatty acids and ahexitol such as polyoxyethylene sorbitol monooleate, or condensationproducts of ethylene oxide with partial esters derived from fatty acidsand hexitol anhydrides, for example polyethylene sorbitan monooleate.The aqueous solutions or suspensions can also contain one or morepreservatives, for example ethyl, or n-propyl p-hydroxybenzoate, one ormore coloring agents, one or more flavoring agents, and one or moresweetening agents, such as sucrose, saccharin or aspartame. In certaininstances, the flavoring agents are the compounds.

Oily suspensions can be formulated by suspending the activeingredient(s) in a vegetable oil, for example arachis oil, olive oil,sesame oil or coconut oil, or in mineral oil such as liquid paraffin.The oily suspensions can contain a thickening agent, for examplebeeswax, hard paraffin or cetyl alcohol. Sweetening agents such as thoseset forth above, and flavoring agents can be added to provide apalatable oral preparation. These compositions can be preserved by theaddition of an anti-oxidant such as butylated hydroxyanisol oralpha-tocopherol.

Dispersible powders and granules suitable for preparation of an aqueoussolutions or suspension by the addition of water provide the activeingredient in admixture with a dispersing or wetting agent, suspendingagent and one or more preservatives. Suitable dispersing or wettingagents and suspending agents are exemplified by those already mentionedabove. Additional excipients, for example sweetening, flavoring andcoloring agents, can also be present. These compositions can bepreserved by the addition of an antioxidant such as ascorbic acid.

Compositions can also be in the form of an oil-in-water emulsion. Theoily phase can be a vegetable oil, for example olive oil or arachis oil,or a mineral oil, for example liquid paraffin or mixtures of these.Suitable emulsifying agents can be naturally-occurring phosphatides, forexample soy bean lecithin, and esters or partial esters derived fromfatty acids and hexitol anhydrides, for example sorbitan monooleate, andcondensation products of the said partial esters with ethylene oxide,for example polyoxyethylene sorbitan monooleate. The emulsions can alsocontain sweetening agents, flavoring agents, preservatives andantioxidants.

Syrups and elixirs can be formulated with sweetening agents, for exampleglycerol, propylene glycol, sorbitol or sucrose. Such formulations canalso contain a demulcent, a preservative, flavoring and coloring agentsand antioxidant.

Compositions can also be formulated in rectal compositions such assuppositories or retention enemas, e.g., containing conventionalsuppository bases such as cocoa butter, polyethylene glycol, or otherglycerides. These compositions can be prepared by mixing the inhibitorswith a suitable non-irritating excipient which is solid at ordinarytemperatures but liquid at the rectal temperature and will thereforemelt in the rectum to release the drug. Such materials include cocoabutter, glycerinated gelatin, hydrogenated vegetable oils, mixtures ofpolyethylene glycols of various molecular weights and fatty acid estersof polyethylene glycol.

Accordingly, pharmaceutical compositions are also provided comprisingthe biguanide compound in a delayed-release formulation suitable fororal administration such as a tablet, capsule, cachet, pill, lozenge,powder or granule, solution, liquid, or suspension. The pharmaceuticalcomposition is preferably in a unit dosage form suitable for singleadministration of precise dosages, e.g., 100 mg, 200 mg, 250, mg, 300mg, 400 mg, 500 mg, 600 mg, 750 mg, 800 mg, or 1000 mg of the desiredbiguanide compound, particularly metformin, phenformin, buformin orimeglimin or a salt thereof. The pharmaceutical composition may compriseconventional pharmaceutical carriers or excipients and the biguanidecompound according to the invention as an active ingredient. They mayfurther comprise other medicinal or pharmaceutical agents, carriers,adjuvants, etc.

Suitable carriers include inert diluents or fillers, water and variousorganic solvents. The compositions can, if desired, contain additionalingredients such as flavorings, binders, excipients and the like. Thusfor oral administration, tablets containing various excipients, such ascitric acid can be employed together with various disintegrants such asstarch or other cellulosic material, alginic acid and certain complexsilicates and with binding agents such as sucrose, gelatin and acacia.Additionally, lubricating agents such as magnesium stearate, sodiumlauryl sulfate and talc are often useful for tableting purposes. Otherreagents such as an inhibitor, surfactant or solubilizer, plasticizer,stabilizer, viscosity increasing agent, or film forming agent can alsobe added. Solid compositions of a similar type can also be employed insoft and hard filled gelatin capsules. Materials include lactose or milksugar and high molecular weight polyethylene glycols. When aqueoussuspensions or elixirs are desired for oral administration the activecompound therein can be combined with various sweetening or flavoringagents, coloring matters or dyes and, if desired, emulsifying agents orsuspending agents, together with diluents such as water, ethanol,propylene glycol, glycerin, or combinations thereof.

Excipients

Any of the compositions or formulations described herein include anycommonly used excipients in pharmaceutics and are selected on the basisof compatibility with the active agent(s) and release profile propertiesof the desired dosage form. Excipients include, but are not limited to,binders, fillers, flow aids/glidents, disintegrants, lubricants,stabilizers, surfactants, and the like. A summary of excipientsdescribed herein, may be found, for example in Remington: The Scienceand Practice of Pharmacy, Nineteeth Ed (Easton, Pa.: Mack PublishingCompany, 1995); Hoover, John E., Remington's Pharmaceutical Sciences,(Easton, Pa.: Mack Publishing Co 1975); Liberman, H. A. and Lachman, L.,Eds., Pharmaceutical Dosage Forms (New York, N.Y.: Marcel Decker 1980);and Pharmaceutical Dosage Forms and Drug Delivery Systems, Seventh Ed(Lippincott Williams & Wilkins 1999), herein incorporated by referencein their entirety.

Binders impart cohesive qualities and include, e.g., alginic acid andsalts thereof; cellulose derivatives such as carboxymethylcellulose,methylcellulose (e.g., Methocel®), hydroxypropylmethylcellulose,hydroxyethyl cellulose, hydroxypropylcellulose (e.g., Klucel®),ethylcellulose (e.g., Ethocel®), and microcrystalline cellulose (e.g.,Avicel®); microcrystalline dextrose; amylose; magnesium aluminumsilicate; polysaccharide acids; bentonites; gelatin;polyvinylpyrrolidone/vinyl acetate copolymer; crospovidone; povidone;starch; pregelatinized starch; tragacanth, dextrin, a sugar, such assucrose (e.g., Dipac®), glucose, dextrose, molasses, mannitol, sorbitol,xylitol (e.g., Xylitab®), and lactose; a natural or synthetic gum suchas acacia, tragacanth, ghatti gum, mucilage of isapol husks,polyvinylpyrrolidone (e.g., Polyvidone® CL, Kollidon® CL, Polyplasdone®XL-10), larch arabogalactan, Veegum®, polyethylene glycol, waxes, sodiumalginate, and the like.

Disintegrants facilitate breakup or disintegration of oral solid dosageforms after administration. Examples of disintegrants include a starch,e.g., a natural starch such as corn starch or potato starch, apregelatinized starch such as National 1551 or Amijel®, or sodium starchglycolate such as Promogel® or Explotab®; a cellulose such as a woodproduct, methylcrystalline cellulose, e.g., Avice10, Avicel® PH101,Avicel® PH102, Avicel® PH105, Eleema® P100, Emcoccl®, Vivaccl®, MingTia®, and Solka-Floc®, methylcellulose, croscarmellose, or across-linked cellulose, such as cross-linked sodiumcarboxymethylcellulose (Ac-Di-Solt), cross-linkedcarboxymethylcellulose, or cross-linked croscarmellose; a cross-linkedstarch such as sodium starch glycolate; a cross-linked polymer such ascrospovidone; a cross-linked polyvinylpyrrolidone; alginate such asalginic acid or a salt of alginic acid such as sodium alginate; a claysuch as Veegum® HV (magnesium aluminum silicate); a gum such as agar,guar, locust bean, Karaya, pectin, or tragacanth; sodium starchglycolate; bentonite; a natural sponge; a resin such as acation-exchange resin; citrus pulp; sodium lauryl sulfate; sodium laurylsulfate in combination starch; and the like.

Lubricants are compounds which prevent, reduce or inhibit adhesion orfriction of materials. Exemplary lubricants include, e.g., stearic acid;calcium hydroxide; talc; sodium stearyl fumerate; a hydrocarbon such asmineral oil, hydrogenated castor oil or hydrogenated vegetable oil suchas hydrogenated soybean oil (Sterotex®); higher fatty acids and theiralkali-metal and alkaline earth metal salts, such as aluminum, calcium,magnesium, zinc; stearic acid, sodium stearates, magnesium stearates,glycerol, talc, waxes, Stearowet® boric acid, sodium benzoate, sodiumacetate, sodium chloride, leucine, a polyethylene glycol or amethoxypolyethylene glycol such as Carbowax™, ethylene oxide polymers,sodium oleate, glyceryl behenate (E.g. Compritol 888 Ato), glyceryldisterate (Precirol Ato 5), polyethylene glycol, magnesium or sodiumlauryl sulfate, colloidal silica such as Syloid™, Carb-O—Si10,DL-leucine, a starch such as corn starch, silicone oil, a surfactant,and the like.

Flow-aids or glidants improve the flow characteristics of powdermixtures. Such compounds include, e.g., colloidal silicon dioxide suchas Cab-o-Sil®; tribasic calcium phosphate, talc, corn starch,DL-leucine, sodium lauryl sulfate, magnesium stearate, calcium stearate,sodium stearate, kaolin, and micronized amorphous silicon dioxide(Syloid®) and the like.

Plasticizers aid in coating of oral solid dosage forms. Exemplaryplasticizers include, but are not limited to, triethyl citrate,triacetin (glyceryl triacetate), acetyl triethyl citrate, polyethyleneglycols (PEG 4000, PEG 6000, PEG 8000), Carbowax 400 (polyethyleneglycol 400), diethyl phthalate, diethyl sebacate, acetyltriethylcitrate,oleic acid, glyceralmonosterate, tributyl citrate, acetylatedmonoglycerides, glycerol, fatty acid esters, propylene glycol, anddibutyl phthalate and the like.

The aforementioned excipients are given as examples only and are notmeant to include all possible choices. Other suitable excipient classesinclude coloring agents, granulating agents, preservatives, anti-foamingagents, solubulizers and the like. Additionally, many excipients canhave more than one role or function, or can be classified in more thanone group; the classifications are descriptive only, and are notintended to limit any use of a particular excipient.

Combination Therapies

The compositions of the embodiments described herein may beco-administered with known therapies for the treatment of any of theconditions described herein. Co-administration can also provide foradditive or synergistic effects, resulting in the need for lower dosagesof a known therapy, the compositions described herein, or both.Additional benefits of co-administration include the reduction intoxicities associated with any of the known therapies.

Co-administration includes simultaneous administration in separatecompositions, administration at different times in separatecompositions, or administration in a composition in which both agentsare present. Thus, in some embodiments, compositions described hereinand a known therapy are administered in a single treatment. In someembodiments, the compositions described herein and a known therapy areadmixed in a resulting composition. In some embodiments, compositionsdescribed herein and the known therapy are administered in separatecompositions or administrations.

Administration of compositions described herein and known therapiesdescribed herein may be by any suitable means. Administration of acomposition described herein and a second compound (e.g., diabetes drugor obesity drug) may be by any suitable means. If the compositionsdescribed herein and a second compound are administered as separatecompositions, they may be administered by the same route or by differentroutes. If the compositions described herein and a second compound areadministered in a single composition, they may be administered by anysuitable route such as, for example, oral administration. In certainembodiments, compositions of metformin or an analog thereof (includingsalts, solvates, polymorphs, hydrates, N-oxides, or prodrugs thereof)and second compounds can be administered to the same region or differentregions of the gastrointestinal tract. For example, metformin or ananalog thereof (including salts, solvates, polymorphs, hydrates,N-oxides, or prodrugs thereof)s can be administered in combination withan anti-diabetic drug to be delivered to the duodenum, jejunum, ileum,or colon.

Therapies, drugs and compounds useful for the treatment of hyperglycemiaand/or diseases or conditions associated therewith, e.g., diabetes maybe administered with the compositions disclosed herein. Diabetic drugsand compounds include, but are not limited to, those that decreasetriglyceride concentrations, decrease glucose concentrations, and/ormodulate insulin (e.g. stimulate insulin production, mimic insulin,enhance glucose-dependent insulin secretion, suppress glucagon secretionor action, improve insulin action or insulin sensitizers, or areexogenous forms of insulin).

Drugs that decrease triglyceride level include but are not limited toascorbic acid, asparaginase, clofibrate, colestipol, fenofibratemevastatin, pravastatin, simvastatin, fluvastatin, or omega-3 fattyacid. Drugs that decrease LDL cholesterol level include but are notlimited to clofibrate, gemfibrozil, and fenofibrate, nicotinic acid,mevinolin, mevastatin, pravastatin, simvastatin, fluvastatin,lovastatin, cholestyrine, colestipol or probucol.

In another aspect, compositions of the embodiments described herein maybe administered in combination with glucose-lowering compounds.

The medication classes of thiazolidinediones (also called glitazones),sulfonylureas, meglitinides, biguanides, alpha-glucosidase inhibitors,DPP-IV inhibitors, and incretin mimetics have been used as adjunctivetherapies for hyperglycemia and diabetes mellitus (type 2) and relateddiseases.

Drugs that decrease glucose level include but are not limited toglipizides, glyburides, exenatide (Byetta®), incretins, sitagliptin(Januvia®), pioglitizone, glimepiride, rosiglitazone, metformin,vildagliptin, saxagliptin (Onglyza™), sulfonylureas, meglitinide (e.g.,Prandin®) glucosidase inhibitor, biguanides (e.g., Glucophage®),repaglinide, acarbose, troglitazone, nateglinide, natural, synthetic orrecombinant insulin and derivatives thereof, and amylin and amylinderivatives.

When administered sequentially, the combination may be administered intwo or more administrations. In an alternative embodiment, it ispossible to administer one or more the biguanide compounds and one ormore additional active ingredients by different routes. The skilledartisan will also recognize that a variety of active ingredients may beadministered in combination with one or more the biguanide compoundsthat may act to augment or synergistically enhance the controlprevention, amelioration, attenuation, or treatment of obesity or eatingdisorders or conditions.

According to the methods provided herein, when co-administered with atleast one other obesity reducing (or anti-obesity) or weight reducingdrug, the compounds of the disclosure may be: (1) co-formulated andadministered or delivered simultaneously in a combined formulation; (2)delivered by alternation or in parallel as separate formulations; or (3)by any other combination therapy regimen known in the art. Whendelivered in alternation therapy, the methods provided may compriseadministering or delivering the active ingredients sequentially, e.g.,in separate solution, emulsion, suspension, tablets, pills or capsules,or by different injections in separate syringes. In general, duringalternation therapy, an effective dosage of each active ingredient isadministered sequentially, i.e., serially, whereas in simultaneoustherapy, effective dosages of two or more active ingredients areadministered together. Various sequences of intermittent combinationtherapy may also be used.

In certain embodiments, compositions provided herein may be used withother commercially available diet aids or other weight loss and/oranti-obesity agents, such as, by way of example, PYY and PYY agonists,GLP-1 and GLP-1 agonists, a DPP-IV inhibitor, CCK and CCK agonists,exendin and exendin agonists, GIP and GIP agonists, amylin and amylinagonists, ghrelin modulators (e.g., inhibitors) and leptin and leptinagonists. In certain instances, compositions comprising the biguanidecompound provided herein are used in combination with amylin, amylinagonists or mimetics. Exemplary amylin agonists or mimetics includepramlintide and related compounds. In certain instances, the compoundsand compositions provided herein are used in combination with leptin,leptin agonists or mimetics. Additional leptin agonists or mimetics canbe identified using the methods described by U.S. Pat. No. 7,247,427which is incorporated by reference herein. In further instances, thecompounds and compositions provided herein increase leptin sensitivityand increase effectiveness of leptin, leptin agonists or mimetics.

Additional anti-obesity agents suitable for use in the subject methodsinclude those that are in current development. Other anti-obesity agentsinclude phentermine, fenfluramine, sibutramine, rimonabant, topiramate,zonisamide, bupropion, naltrexone, lorcaserin, or relatedsympathomimetics and orlistat or other intestinal lipase inhibitors,alone or in combination. Therapies, drugs and compounds useful for thetreatment of weight loss, binge eating, food addictions and cravings maybe administered with the compositions described herein. For example, thepatient may further be administered at least one other drug which isknown to suppress hunger or control appetite. Such therapies drugs andcompounds include but are not limited to phenteramines such as Meridia®and Xenical®. Additional therapies, drugs and compounds are known in theart and contemplated herein.

As such, in one aspect, the compound may be used as part of acombination therapy for the control, prevention or treatment of obesityor eating disorders or conditions. Compounds used as part of acombination therapy to treat obesity or reduce weight include, but arenot limited to, central nervous system agents that affectneurotransmitters or neural ion channels, including antidepressants(bupropion), noradrenalin reuptake inhibitors (GW320659), selective 5HT2c receptor agonists, antiseizure agents (topiramate, zonisamide), somedopamine antagonists, and cannabinoid-1 receptor antagonists (CB-1receptor antagonists) (rimonabant); leptin/insulin/central nervoussystem pathway agents, including leptin analogues, leptin transportand/or leptin receptor promoters, ciliary neurotrophic factor (Axokine),neuropeptide Y and agouti-related peptide antagonists,pro-opiomelanocortin and cocaine and amphetamine regulated transcriptpromoters, .alpha.-melanocyte-stimulating hormone analogues,melanocortin-4 receptor agonists, and agents that affect insulinmetabolism/activity, which include protein-tyrosine phosphatase-1Binhibitors, peroxisome proliferator activated receptor-gamma receptorantagonists, short-acting bromocriptine (ergoset), somatostatin agonists(octreotide), and adiponectin/Acrp30 (Famoxin or Fatty Acid MetabolicOxidation Inducer); gastrointestinal-neural pathway agents, includingthose that increase cholecystokinin activity (CCK), PYY activity, NPYactivity, and PP activity, increase glucagon-like peptide-1 activity(exendin 4, liraglutide, dipeptidyl peptidase IV inhibitors), and thosethat decrease ghrelin activity, as well as amylin analogues(pramlintide); agents that may increase resting metabolic rate(selective (3-3 stimulators/agonist, uncoupling protein homologues, andthyroid receptor agonists); other more diverse agents, including melaninconcentrating hormone antagonists, phytostanol analogues, functionaloils, P57, amylase inhibitors, growth hormone fragments, syntheticanalogues of dehydroepiandrosterone sulfate, antagonists of adipocyte11B-hydroxysteroid dehydrogenase type I activity,corticotropin-releasing hormone agonists, inhibitors of fatty acidsynthesis (cerulenin and C75), carboxypeptidase inhibitors,indanone/indanols, amino sterols (trodusquemine/trodulamine), and othergastrointestinal lipase inhibitors (ATL962); amphetamines, such asdextroamphetamine; other sympathomimetic adrenergic agents, includingphentermine, benzphetamine, phendimetrazine, mazindol, anddiethylpropion.

Other compounds include ecopipam; oxyntomodulin (OM); inhibitors ofglucose-dependent insulinotropic polypeptide (GIP); gastrin-releasingpeptide; neuromedin B; enterostatin; amfebutamone, SR-58611; CP-045598;AOD-0604; QC-BT16; rGLP-1; 1426 (HMR-1426); N¬5984; ISIS-113715;solabegron; SR-147778; Org-34517; melanotan-II; cetilistat; c-2735;c-5093; c¬2624; APD-356; radafaxine; fluasterone; GP-389255; 856464;S-2367; AVE-1625; T-71; olcoyl-estrone; peptide YY [3-36] intranasal;androgen receptor agonists; PYY 3-36; DOV-102677; tagatosc; SLV-319;1954 (Aventis Pharma AG); oxyntomodulin, Thiakis; bromocriptine, PLIVA;diabetes/hyperlipidemia therapy, Yissum; CKD-502; thyroid receptor betaagonists; beta-3 adrenoceptor agonist; CDK-A agonists; galaninantagonist; dopamine D1/D2 agonists; melanocortin modulators;verongamine; neuropeptide Y antagonists; melanin-concentrating hormonereceptor antagonists; dual PPAR alpha/gamma agonists; CGEN-P-4; kinaseinhibitors; human MCH receptor antagonists; GHS-R antagonists; ghrelinreceptor agonists; DG70 inhibitors; cotinine; CRF-BP inhibitors;urocortin agonists; UCL-2000; impentamine; .beta.-3 adrenergic receptor;pentapeptide MC4 agonists; trodusquemine; GT-2016; C-75; CPOP; MCH-1receptor antagonists; RED-103004; aminosterols; orexin-1 antagonists;neuropeptide Y5 receptor antagonists; DRF-4158; PT-15; PTPaseinhibitors; A37215; SA-0204; glycolipid metabolites; MC-4 agonist;produlestan; PTP-1B inhibitors; GT-2394; neuropeptide Y5 antagonists;melanocortin receptor modulators; MLN-4760; PPAR gamma/delta dualagonists; NPY5RA-972; 5-HT2C receptor agonist; neuropeptide Y5 receptorantagonists (phenyl urea analogs); AGRP/MC4 antagonists; neuropeptide Y5antagonists (benzimidazole); glucocorticoid antagonists; MCHR1antagonists; Acetyl-CoA carboxylase inhibitors; R-1496; HOB1 modulators;NOX-B11; peptide YY 3-36 (eligen); 5-HT 1 modulators; pancreatic lipaseinhibitors; GRC-1087; CB-1 antagonists; MCH-1 antagonists; LY-448100;bombesin BRS3 agonists; ghrelin antagonists; MC4 antagonists;stearoyl-CoA desaturase modulators; H3 histamine antagonists; PPARpanagonists; EP-01492; hormone-sensitive lipase inhibitors; fattyacid-binding protein 4 inhibitors; thiolactone derivatives; proteintyrosine phosphatase 1B inhibitors; MCH-1 antagonist; P-64; PPAR gammaligands; melanin concentrating hormone antagonists; thiazolegastroprokinetics; PA-452; T-226296; A-331440; immunodrug vaccines;diabetes/obesity therapeutics (Bioagency, Biofrontera Discovery GmbH);P-7 (Genfit); DT-011 M; PTP1B inhibitor; anti-diabetic peptideconjugates; KATP agonists; obesity therapeutics (Lexicon); 5-HT2agonists; MCH-1 receptor antagonists; GMAD-1/GMAD-2; STG-a-MD;neuropeptide Y antagonist; angiogenesis inhibitors; G protein-coupledreceptor agonists; nicotinic therapeutics (ChemGenex); anti-obesityagents (Abbott); neuropeptide Y modulators; melanin concentratinghormone; GW-594884A; MC-4R agonist; histamine H3 antagonists; orphanGPCR modulators; MITO-3108; NLC-002; HE-2300; IGF/IBP-2-13; 5-HT2Cagonists; ML-22952; neuropeptide Y receptor antagonists; AZ-40140;anti-obesity therapy (Nisshin Flour); GNTI; melanocortin receptormodulators; alpha-amylase inhibitors; neuropeptide Y1 antagonist; beta-3adrenoceptor agonists; ob gene products (Eli Lilly & Co.); SWR-0342-SA;beta-3 adrenoceptor agonist; SWR-0335; SP-18904; oral insulin mimetics;beta 3 adrenoceptor agonists; NPY-1 antagonists; .beta.-3 agonists;obesity therapeutics (7TM Pharma); 1 ibeta-hydroxysteroid dehydrogenase(HSD)1 inhibitors; QRX-431; E-6776; RT-450; melanocortin-4 antagonists;melanocortin 4 receptor agonists; obesity therapeutics (CuraGen); leptinmimetics; A-74498; second-generation leptin; NBI-103; CL-314698;CP-114271; beta-3 adrenoceptor agonists; NMI 8739; UCL-1283; BMS-192548;CP-94253; PD-160170; nicotinic agonist; LG-100754; SB-226552; LY-355124;CKD-711; L-751250; PPAR inhibitors; G-protein therapeutics; obesitytherapy (Amylin Pharmaceuticals Inc.); BW-1229; monoclonal antibody(ObeSys/CAT); L-742791; (S)sibutramine; MBU-23; YM-268; BTS-78050;tubby-like protein genes; genomics (eating disorders; Allelix/Lilly);MS-706; GI-264879A; GW-409890; FR-79620 analogs; obesity therapy(Hybrigenics SA); ICI-198157; ESP-A; 5-HT2C agonists; PD-170292;AIT-202; LG-100641; GI-181771; anti-obesity therapeutics (Genzyme);leptin modulator; GHRH mimetics; obesity therapy (YamanouchiPharmaceutical Co. Ltd.); SB-251023; CP-331684; BIBO-3304;cholcstcn-3-oncs; LY-362884; BRL-48962; NPY-1 antagonists; A-71378;.RTM.-didesmethylsibutramine; amide derivatives; obesity therapeutics(Bristol-Myers Squibb Co.); obesity therapeutics (Ligand PharmaceuticalsInc.); LY-226936; NPY antagonists; CCK-A agonists; FPL-14294; PD-145942;ZA-7114; CL-316243; SR-58878; R-1065; BIBP-3226; HP-228; talibegron;FR-165914; AZM-008; AZM-016; AZM-120; AZM-090; vomeropherin; BMS-187257;D-3800; AZM-131; gene discovery (Axys/Glaxo); BRL¬26830A; SX-013; ERRmodulators; adipsin; AC-253; A-71623; A-68552; BMS-210285; TAK-677;MPV-1743; obesity therapeutics (Modex); GI-248573; AZM-134; AZM-127;AZM-083; AZM-132; AZM-115; exopipam; SSR-125180; obesity therapeutics(Melacure Therapeutics AB); BRL-35135; SR-146131; P-57; AZM-140;CGP-71583A; RF-1051; BMS-196085; manifaxine; beta-3 agonists; DMNJ(Korea Research Institute of Bioscience and Biotechnology); BVT-5182;LY-255582; SNX-024; galanin antagonists; neurokinin-3 antagonists;dexfenfluramine; mazindol; diethylpropion; phendimetrazine;benzphetamine; amfebutmone; sertraline; metformin; AOD-9604; ATL-062;BVT-933; GT389-255; SLV319; HE-2500; PEG-axokine; L-796568; and ABT-239.

In some embodiments, compounds for use in combination with a compositioncomprising the biguanide compound provided herein include rimonabant,sibutramine, orlistat, PYY or an analog thereof, CB-1 antagonist,leptin, phentermine, and exendin analogs. Exemplary dosing rangesinclude phentermine resin (30 mg in the morning), fenfluraminehydrochloride (20 mg three times a day), and a combination ofphentermine resin (15 mg in the morning) and Lorcaserin (30 mg beforethe evening meal), and sibutramine (10-20 mg). Weintraub et al. (1984)Arch. Intern. Med. 144:1143-1148.

In further embodiments, compounds for use in combination with acomposition provided herein include GPR119 agonists (e.g., anandamide;AR-231, 453; MBX-2982; Oleoylethanolamide; PSN-365,963; PSN-632,408;palmitoylethanolamide), GPR120 agonists (e.g., omega-3 fatty acidsincluding, but not limited to, a-linolenic acid, docosapentaenoic acid,docosahexaenoic acid, eicosatrienoic acid, eicosatetraenoic acid,eicosapentaenoic acid, heneicosapentaenoic acid, hexadecatrienoic acid,stearidonic acid, tetracosahexaenoic acid and tetracosapentaenoic acid),and GPR 40, GPR41 and GPR 43 agonists (e.g., free fatty acids includingshort-, medium-, and long-chain saturated and unsaturated fatty acids).

In some embodiments, a composition provided herein is used as anadjunctive therapy to a bariatric surgical procedure. Bariatric surgeryis a procedure for weight loss and relates to modifications with thegastrointestinal tract and includes such procedures as gastric banding,sleeve gastrectomy, GI bypass procedure (e.g., roux en Y, biliaryduodenal bypass, loop gastric bypass), intragastric balloon, verticalbanded, gastroplasty, endoluminal sleeve, biliopancreatic diversion, andthe like. In certain instances, a the composition provided herein isadjunctive to gastric banding. In certain instances, a composition isadjunctive to GI bypass procedures. In yet other instances, acomposition provided herein is adjunctive to sleeve gastrectomy. Incertain embodiments, a composition provided herein as an adjunctivetherapy to bariatric surgery is administered prior to the bariatricprocedure. In certain embodiments, a composition provided herein as anadjunctive therapy to bariatric surgery is administered after thebariatric procedure. In certain instances, when used as adjunctivetherapy, the dosage and amounts of a composition provided herein may beadjusted as needed with respect to the bariatric procedure. For example,amounts of a composition provided herein administered as an adjuncttherapy to a bariatric procedure may be reduced by one-half of normaldosages or as directed by a medical professional.

Combination therapy can be exploited, for example, in modulatingmetabolic syndrome (or treating metabolic syndrome and its relatedsymptoms, complications and disorders), wherein the compositionsprovided herein can be effectively used in combination with, forexample, the active agents discussed above for modulating, preventing ortreating diabetes, obesity, hyperlipidemia, atherosclerosis, and/ortheir respective related symptoms, complications and disorders.

Methods for Evaluating Treatment

Evaluation of Treatment of Diabetes

The effect of the biguanide compound treatment of the invention onaspects of diabetic disease can be evaluated according to methods knownin the art and common practiced by physicians treating diabeticpatients.

Efficacy of treatment of diabetes/metabolic syndrome anddiabetes-associated conditions with the compositions and methodsdescribed herein can be assessed using assays and methodologies known inthe art. By way of example, quantitative assessment of renal functionand parameters of renal dysfunction are well known in the art. Examplesof assays for the determination of renal function/dysfunction includeserum creatinine level; creatinine clearance rate; cystatin C clearancerate, 24-hour urinary creatinine clearance, 24-hour urinary proteinsecretion; Glomerular filtration rate (GFR); urinary albumin creatinineratio (ACR); albumin excretion rate (AER); and renal biopsy.

Quantitative assessment of pancreatic function and parameters ofpancreatic dysfunction or insufficiency are also well known in the art.Examples of assays for the determination of pancreasfunction/dysfunction include evaluating pancreatic functions usingbiological and/or physiological parameters such as assessment of isletsof Langerhans size, growth and/or secreting activity, beta-cells size,growth and/or secreting activity, insulin secretion and circulatingblood levels, glucose blood levels, imaging of the pancreas, andpancreas biopsy, glucose uptake studies by oral glucose challenge,assessment of cytokine profiles, blood-gas analysis, extent ofblood-perfusion of tissues, and angiogenesis within tissues.

Additional assays for treatment of diabetes and diabetes-associatedconditions are known in the art and are contemplated herein.

Evaluation of Treatment of Weight Loss, Obesity and Eating Disorders

In treatment of obesity it is desired that weight and/or fat is reducedin a patient. By reducing weight it is meant that the patient loses aportion of his/her total body weight over the course of treatment(whether the course of treatment be days, weeks, months or years).Alternatively, reducing weight can be defined as a decrease inproportion of fat mass to lean mass (in other words, the patient haslost fat mass, but maintained or gained lean mass, without necessarily acorresponding loss in total body weight). An effective amount of a thebiguanide compound treatment administered in this embodiment is anamount effective to reduce a patient's body weight over the course ofthe treatment, or alternatively an amount effective to reduce thepatient's percentage of fat mass over the course of the treatment. Incertain embodiments, the patient's body weight is reduced, over thecourse of treatment, by at least about 1%, by at least about 5%, by atleast about 10%, by at least about 15%, or by at least about 20%.Alternatively, the patient's percentage of fat mass is reduced, over thecourse of treatment, by at least 1%, at least 5%, at least 10%, at least15%, at least 20%, or at least 25%.

Total body weight and fat content can be measured at the end of thedietary period. In rats, a frequently used method to determine totalbody fat is to surgically remove and weigh the retroperitoneal fat pad,a body of fat located in the retroperitoneum, the area between theposterior abdominal wall and the posterior parietal peritoneum. The padweight is considered to be directly related to percent body fat of theanimal. Since the relationship between body weight and body fat in ratsis linear, obese animals have a correspondingly higher percent of bodyfat and retroperitoneal fat pad weight.

In embodiments wherein methods of treating, reducing, or preventing foodcravings in a patient are provided, food cravings can be measured byusing a questionnaire, whether known in the art or created by the personstudying the food cravings. Such a questionnaire would preferably rankthe level of food cravings on a numerical scale, with the patientmarking 0 if they have no food cravings, and marking (if on a scale of1-10) 10 if the patient has severe food cravings. The questionnairewould preferably also include questions as to what types of food thepatient is craving. Binge eating can be determined or measured using aquestionnaire and a Binge Eating Scale (BES). Binge eating severity canbe divided into three categories (mild, moderate, and severe) based onthe total BES score (calculated by summing the scores for eachindividual item). Accordingly, methods are provided for reducing the BESscore of a patient comprising administering to a patient in need thereofa compound treatment in an amount effective to reduce the BES score ofthe patient. In some embodiments, administration of a compound treatmentchanges the BES category of the patient, for example, from severe tomoderate, from severe to mild, or from moderate to mild.

Pre-Treatment Evaluation of Patient Hormonal Profile

In some embodiments, patients are pre-evaluated for expression ofmetabolic hormones using methods described herein. The therapy providedto the individual can thus be targeted to his or her specific needs. Inembodiments, a patient's hormonal profile is pre-evaluated and dependingon the changes that the physician desires to affect, a certaindetermined amount of the compound/metabolite combination isadministered. The evaluation process can be repeated and the treatmentadjusted accordingly at any time during or following treatment.

Hormone Assays

In embodiments, the levels of hormones assayed in association with themethods of the invention, including, but not limited to, GLP-1, GLP-2,GIP, oxyntomodulin, PYY, CCK, glycentin, insulin, glucagon, ghrelin,amylin, uroguanylin, C-peptide and/or combinations thereof are detectedaccording to standard methods described in the literature. For example,proteins can be measured by immunological assays, and transcriptionproducts by nucleic acid amplification techniques. Functional assaysdescribed in the art can also be used as appropriate. In embodiments,samples assayed comprise cultured cells, patient cell or tissue samples,patient body fluids, e.g., blood or plasma, etc. Similarly, the levelsof analytes (e.g., glucose, triglycerides, HDL, LDL, apoB and the like)assayed in association with the methods of the invention are detectedaccording to any known method.

For example, immunofluorescence can be used to assay for GLP-1. Cellscan be grown on matrigel-coated cover slips to confluent monolayers in12-well plates at 37° C., fixed in 4% paraformaldehyde inphosphate-buffered saline (PBS) and incubated with primary antiserum(e.g., rabbit anti-alpha gustducin, 1:150; Santa Cruz Biotechnology, andrabbit anti-GLP-1, Phoenix) overnight at 4° C. followingpermeabilization with 0.4% Triton-X in PBS for 10 minutes and blockingfor 1 hour at room temperature. Following three washing steps withblocking buffer, the appropriate secondary antibody is applied(AlexaFluor 488 anti-rabbit immunoglobulin, 1:1000; Molecular Probes)for 1 hour at room temperature. After three washing steps, the cells canbe fixed in Vcctashield medium and the immunofluorescence visualized.

GLP-1 RNA isolated from cells can be assayed using RT-PCR. RT-PCR RNAisolation from cells can be performed using standard methodology. TheRT-PCR reaction can be performed in a volume of 50 pl in a Peltierthermal cycler (PTC-225 DNA Engine Tetrad Cycler; MJ Research), usingpublished primer sequences (Integrated DNA Technologies). Reversetranscription can be performed at 50° C. for 30 minutes; after aninitial activation step at 95° C. for 15 minutes. PCR can be performedby denaturing at 94° C. for 1 minute, annealing at 55° C. for 1 minuteand extension at 72° C. for 1 minute for 40 cycles, followed by a finalextension step at 72° C. for 10 minutes. Negative controls can beincluded as appropriate, for example, by substituting water for theomitted reverse transcriptase or template. The control can be RNAisolated from, e.g., rat lingual epithelium. PCR products can beseparated in 2% agarose gel with ethidium bromide, and visualized underUV light.

Radioimmunoassay (RIA) for total GLP-1 in patient blood samples can beperformed as described in the art, e.g., by Laferrere, et al., 2007,“Incretin Levels and Effect are Markedly Enhanced 1 Month afterRoux-en-Y Gastric Bypass Surgery in Obese Patients with Type 2 Diabetes,Diabetes Care 30(7):1709-1716 (using commercially available materialsobtained from Phoenix Pharmaceutical, Belmont, Calif.). The authorsdescribe measuring the effect of GIP and GLP-1 on secretion of insulinby measuring the difference in insulin secretion (area under the curve,or AUC) in response to an oral glucose tolerance test and to anisoglycemic intravenous glucose test.

Measurement of plasma concentrations of GLP-1, GIP, glucagon, insulin, Cpeptide, pancreatic peptide, nonesterified fatty acids, glutamic aciddecarboxylase antibodies, and islet antigen antibodies, is described,e.g., by Toft-Nielsen, et al., 2001, “Determinants of the ImpairedSecretion of Glucagon-Like Peptide-1 in Type 2 Diabetic Patients,” J.Clin. End. Met. 86(8):3717-3723. The authors describe the use ofradioimmunoassay for GLP-1 to measure plasma concentrations of amidatedGLP-1-(7-36), using antibody code no. 89390. This assay measures the sumof GLP-1-(7-36) and its metabolite GLP-1-(9-36). The authors describemeasurement of GIP using C-terminally directed antibody code no. R65(RIA), that reacts 100% with a human GIP but not with 8-kDA GIP.

GLP-1 and PYY can be directly assayed in the supernatant from venouseffluents as described by, e.g., Claustre, et al. (1999, “Stimulatoryeffect of (3-adrenergic agonists on ileal L cell secretion andmodulation by a-adrenergic activation, J. Endocrin. 162:271-8). (Seealso Plaisancie' et al., 1994, “Regulation of glucagon-likepeptide-1-(7-36) amide secretion by intestinal neurotransmitters andhormones in the isolated vascularly perfused rat colon,” Endocrinology135:2398-2403 and Plaisancie' et al., 1995, “Release of peptide YY byneurotransmitters and gut hormones in the isolated, vascularly perfusedrat colon,” Scandinavian Journal of Gastroenterology 30:568-574.) Inthis method, the 199D anti-GLP-1 antibody is used at a 1:250 000dilution. This antibody reacts 100% with GLP-1-(7-36) amide, 84% withGLP-1-(1-36) amide, and less than 0.1% with GLP-1-(1-37), GLP-1-(7-37),GLP-2, and glucagon. PYY is assayed with the A4D anti-porcine PYYantiserum at a 1:800 000 dilution.

Methods for assaying GLP-1 and GIP are also described elsewhere in theart, e.g., by Jong, et al., PNAS, 2007.

PYY can also be assayed in blood using a radioimmunoassay as describedby, e.g., Weickert, et al., 2006, “Soy isoflavones increase preprandialpeptide YY (PYY), but have no effect on ghrelin and body weight inhealthy postmenopausal women” Journal of Negative Results inBioMedicine, 5:11. Blood is collected in ice-chilled EDTA tubes for theanalysis of glucose, ghrelin, and PYY. Following centrifugation at 1600g for 10 minutes at 4° C., aliquots were immediately frozen at −20° C.until assayed. All samples from individual patients were measured in thesame assay. The authors described measuring immunoreactive total ghrelinwas measured by a commercially available radioimmunoassay (PhoenixPharmaceuticals, Mountain View, Calif., USA). (See also Weickert, etal., 2006, “Cereal fiber improves whole-body insulin sensitivity inoverweight and obese women,” Diabetes Care 29:775-780). Immunoreactivetotal human PYY is measured by a commercially available radioimmunoassay(LINCO Research, Missouri, USA), using 125I-labeled bioactive PYY astracer and a PYY antiserum to determine the level of active PYY by thedouble antibody/PEG technique. The PYY antibody is raised in guinea pigsand recognizes both the PYY 1-36 and PYY 3-36 (active) forms of humanPYY.

SGLT-1, the intestinal sodium-dependent glucose transporter 1, is aprotein involved in providing glucose to the body. It has been reportedto be expressed in response to sugar in the lumen of the gut, through apathway involving T1R3 (Margolskee, et al., 2007 “T1R3 and gustducin ingut sense sugars to regulate expression of Na+-glucose cotransporter 1,”Proc Natl Acad Sci USA 104, 15075-15080”). Expression of SGLT-1 can bedetected as described, e.g., by Margolskee, et al., for example, usingquantitative PCR and Western Blotting methods known in the art.Measurement of glucose transport has been described in the literature,e.g., by Dyer, et al., 1997, Gut 41:56-9 and Dyer, et al., 2003, Eur. J.Biochem 270:3377-88. Measurement of glucose transport in brush bordermembrane vesicles can be made, e.g., by initiating D-glucose uptake bythe addition of 100 pl of incubation medium containing 100 mM NaSCN (orKSCN), 100 mM mannitol, 20 mM Hepes/Tris (pH 7.4), 0.1 mM MgSO4, 0.02%(wt/vol) NaN3, and 0.1 mM D-[U14C]glucose to BBMV (100 μg of protein).The reaction is stopped after 3 sec by addition of 1 ml of ice-cold stopbuffer, containing 150 mM KSCN, 20 mM Hepes/Tris (pH 7.4), 0.1 mM MgSO4,0.02% (wt/vol) NaN3, and 0.1 mM phlorizin. A 0.9-ml portion of thereaction mixture is removed and filtered under vacuum through a 0.22-[tmpore cellulose acetate/nitrate filter (GSTF02500; Millipore, Bedford,Mass.). The filter is washed five times with 1 ml of stop buffer, andthe radioactivity retained on the filter is measured by liquidscintillation counting.

Examples Example 1: Enteroendocrine Production of PYY, GLP-1 (Active)and GLP-1 (Total) and Reduction of Glucose and Insulin is Independent ofPlasma Absorption of Metformin Example 1.1 Materials and Methods

Population: Approximately 18 eligible male and female subjects, 18 to 65years of age, with a BMI of 25.0 to 35.0 kg/m², were randomized in thisstudy. To be eligible, each subject also met the following criteria: (a)was not breastfeeding; (b) had a negative pregnancy test result (humanchorionic gonadotropin, beta subunit); (c) surgically sterile,postmenopausal, or if of childbearing potential, practiced appropriatebirth control during the entire duration of the study; (d) had aphysical examination with no clinically significant abnormalities,including but not limited to the following conditions: (i) Hepaticdisease; (ii) Renal disease; (iii) gastrointestinal disease; (iv)Endocrine disorder, including diabetes; (v) Cardiovascular disease; (vi)Seizure disorder; (vii) Organ transplantation; and (viii) Chronicinfection; and (e) an ability to understand and willingness to adhere toprotocol requirements.

Formulations

The metformin DR formulation was a US-supplied commercially availablefilm-coated immediate-release tablet containing 500 mg metforminhydrochloride, to which additional coatings (a seal coating and anenteric coating) were applied in order to delay release of the drug inthe GI tract until the tablet reached a pH 6.5 region of the distalsmall intestine. The tablets were white, biconvex, circular-shapedcoated tablets, each containing 500 mg metformin hydrochloride. Inactiveingredients in the commercially available tablet included povidone,magnesium stearate, hypromellose, and polyethylene glycol. Inactiveingredients in the additional coating systems included hypromellose,triacetin, talc, methacrylic acid copolymer (Eudragit® L30 D-55),poly(methyl acrylate-co-methyl methacrylate-co-methacrylic acid) 7:3:1(Eudragit® FS 30 D), sodium lauryl sulfate, polysorbate 80, glycerylmonostearate, and triethyl citrate.

The metformin IR formulation was the identical US-supplied commerciallyavailable film-coated immediate-release tablet containing 500 mgmetformin hydrochloride, to which only the additional seal coating isapplied. No delayed-release (enteric) coating was applied. Inactiveingredients in the additional seal coating system included hypromellose,triacetin and talc.

The metformin formulations were supplied to the site as bulk tabletspackaged in screw cap containers labeled with container number and lotnumber. All study medications were stored in cool and dry conditions asindicated on the label, and used only as directed by study personnel.Study medication was dispensed by the unblinded site pharmacist or studypersonnel according to the randomization scheme at the beginning of eachtreatment period.

Administration

Study medication was dispensed by an unblinded site pharmacist or studypersonnel according a randomization scheme at Visits 2 and 4. At the endof Visits 2 and 4, subjects were discharged from the clinic withassigned study medications and with instructions for self-administrationuntil they returned for their next study visit (Visit 3 or 5).

Study medication was administered orally as intact tablets (swallowedwhole, not chewed or crushed), and with water. The first dose and thelast two doses of study medication for each treatment period wereadministered to subjects by qualified study site personnel (first doseat Visits 2 and 4 and last two doses at Visits 3 and 5). Subjectsself-administered the assigned study medications according toinstructions until they returned for their next study visit (Visit 3 or5). Study site personnel contacted subjects by telephone on the secondday of dosing of each treatment period to assess compliance and adverseevents through non-directed questioning. If the subject was experiencingsignificant gastrointestinal symptoms, at the investigator's discretion,subjects were instructed not to dose escalate.

The procedures performed during the study are listed in Tables 1-3below.

TABLE 1 Study Plan (Protocol LCP0C6) Treatment Period 1 Treatment Period2 Base- Day 2 End Base- Day 2 End of line of Treat- of line of Treat-Period 2/ of ment Period of ment Period Period Period 1 Period PeriodStudy Early 1 Phone Visit 2 Phone Termination Termi- Evaluation ScreenVisit 2 Call [1] 3 Visit 4 Call [1] Visit 5 nation Fast (>8 HoursOvernight) X X X X X Informed Consent X Complete Medical History XPhysical Examination and Height X Body Weight and Vital Signs X X X X XX Chemistry, Hematology, Urinalysis X X X Pregnancy Test (Females) [2] XX X Randomization X Timed Blood Sampling [3] X X X X Study MedicationAdministration [4] X X X X Dispense Study Medication X X StudyMedication Compliance Assessment and Collection X X Dose EscalationPhone Call X X Concomitant Medications Assessment X X X X X X [1] Phonecalls to assess compliance and adverse events through non-directedquestioning and to remind subjects to dose escalate [2] Pregnancy testrequired on all female subjects unless subject has had a hysterectomy oris postmenopausal. [3] GLP-1, PYY, plasma glucose, insulin, andtriglycerides at Visits 2 and 4; GLP-1, PYY, plasma glucose, insulin,triglycerides and metformin at Visits 3 and 5. After meal challenge atVisit 2 and Visit 4. Evening dose on Day 4 and morning dose on Day 5 atVisit 3 and Visit 5.

TABLE 2 Schedule of Standardized Breakfast and Blood Sampling Profile atVisit 2 and Visit 4 Standardized Collect 6-mL blood Breakfast Time(minutes) samples [1] Administration [2] −15 X −5 X 0 X 30 X 45 X 60 X90 X 120 X 150 X 180 X 210 X 240 X 270 X 300 X 330 X [1] 6-mL bloodvolume total per sampling time point for assessment of PYY, GLP-1,plasma glucose, insulin, and triglycerides. [2] Subjects are to beinstructed to consume the standardized breakfast within 20 minutes.

TABLE 3 Day 5 Schedule of Dosing, Standardized Breakfast and BloodSampling Profile at Visit 3 and Visit 5 Standardized Collect 6-mL bloodBreakfast Dose Study Collect 2-mL blood Time (minutes) samples [1]Administration [2] Medication sample [3] −245 X −240 X −120 X −15 X −5 XX 0 X 30 X X 45 X X 60 X X 90 X X 120 X X 150 X X 180 X X 210 X X 240 XX 270 X X 300 X X 330 X X 360 X 420 X 480 X [1] 6-mL blood volume totalper sampling time point for assessment of PYY, GLP-1, plasma glucose,insulin, and triglycerides. [2] Subjects are to be instructed to consumethe standardized breakfast within 20 minutes. [3] 2-mL blood volumetotal per sampling time point for assessment of metformin.

Pharmacodynamic Assessments

Blood samples were collected according to the schedules presented inTables 1, 2, and 3, and as described above. Fasting and postprandialplasma concentrations of gut hormones GLP-1 and PYY, as well asconcentrations of plasma glucose, insulin, and triglycerides weremeasured by analytical methods. Blood samples from each visit wasprocessed and stored at −70° C. for future exploratory analysis ofadditional hormones.

Pharmacokinetic Assessments

Blood samples were collected according to the schedules presented inTables 1, 2, and 3, and as described above. Plasma metforminconcentrations were measured by analytical methods. Blood samples fromeach visit were processed and stored at −70° C. for future exploratoryanalysis of additional hormones.

Clinical Laboratory Evaluations

Samples were collected according to the schedules presented in Tables 1,2 and 3, and in the preceding section.

Chemistry

Chemistry assessments included the following: urea nitrogen, creatinine,total protein, albumin, uric acid, total bilirubin, alkalinephosphatase, alanine aminotransferase, aspartate aminotransferase, gammaglutamyltranspeptidase, creatine phosphokinase, glucose, sodium,potassium, chloride, bicarbonate, phosphorus, lactate, and calcium (orother approved routine chemistry panels.

Hematology

Hematology assessments included the following: red cell count,hemoglobin, hematocrit, white cell count, platelets, differential count,mean cell volume, mean corpuscular hemoglobin, and mean corpuscularhemoglobin concentration (or other approved routine hematologyassessments).

Urinalysis

Urinalysis assessments included the following: pH, specific gravity,glucose, blood, ketones, and protein (or other approved routineurinalysis).

Pregnancy Testing

All female subjects, regardless of childbearing status (unless subjectwas postmenopausal or had a hysterectomy), provided blood or urine forpregnancy tests. Study medication was not administered unless a negativeresult was obtained.

Vital Signs and Other Observations Related to Safety

Clinically significant abnormalities in vital signs and otherobservations related to safety were followed up by the investigator andevaluated with additional tests if necessary, until the underlying causewas diagnosed or resolution occurred.

Vital Signs

Vital sign measurements included sitting systolic and diastolic bloodpressure, heart rate, and body temperature. Vital signs were measuredafter the subject rested for approximately 5 minutes and with thesubject in a sitting position. The blood pressure measurement wasrepeated after at least 30 seconds and the average of the two readingsrecorded.

Example 1.2: Results

The study design and event timeline are shown in FIGS. 1-2 . Shown inTables 4 and 5 below are the resulting subject disposition andpopulation (Table 4) and the demographic and baseline characteristics of18 subjects (Table 5).

TABLE 4 Subject Disposition and Population Parameter Result Randomized18 Completed 17 Withdrawal (positive drug test) 1 Evaluable Population16

-   -   2 subjects excluded from evaluable population; 1 withdrawn and 1        could not complete test meal at end of Treatment Period 2

TABLE 5 Demographic and Baseline Characteristics (n = 18) ParameterResult Gender (M/F) 9/9 Mean Age (yr) ± SD 44 ± 10 Race 9 Caucasian, 7Hispanic, 2 black Mean BMI (kg/m2) ± SD 29.3 ± 2.8 

FIG. 3 demonstrates that ingestion of Metformin DR minimized adsorptionof metformin in the plasma compared to Metformin IR. The area under thecurve (AUC) and Cmax values for Metformin DR and Metformin IR areprovided in Table 6 below.

TABLE 6 Metformin Plasma Pharmacokinetics LS Mean Ratio ReMet/MetforminP Value Abs AUC 0.83 0.02 Abs Cmax 0.73 0.003 Incremental Cmax 0.45<0.001

FIG. 4A-C shows an increase in meal-enhanced gut hormones in 16 subjectsafter treatment of Metformin DR comparable to that of Metformin IR,although treatment with Metformin DR minimized the systemic level ofmetformin compared to Metformin IR (FIG. 3 ). Additionally, FIGS. 5A-Bshow a reduction in meal-enhanced glucose and insulin after treatmentwith Metformin DR in 16 subjects comparable to that of Metformin IR.FIG. 6 shows that treatment with Metformin DR results in a similar PYYresponse as Metformin IR, but has a lower systemic exposure. FIGS. 7A-Bshow that the metformin PK/PD relationship was dissociable in at leastone patient.

Example 2—A Randomized, Crossover Study to Assess Steady-State PK and PDof Delayed-Release and Immediate Release Metformin in Subjects with Type2 Diabetes Mellitus

This randomized, crossover study assessed the steady-statepharmacokinetics and pharmacodynamics (glucose, insulin, glucagon-likepeptide-1 [GLP-1], and peptide YY [PYY], of 500 mg and 1000 mg metformindelayed-release (Metformin DR), 1000 mg metformin immediate-release(Metformin IR), and 500 mg Metformin IR+1000 mg Metformin DR in subjectswith type 2 diabetes mellitus. Subjects managing their diabetes withoral anti-diabetic therapy must have been off of those medications forat least the fourteen days immediately prior to randomization.

Each treatment period was five days long and separated by washoutintervals of seven days. Each treatment period contained a standardizedbreakfast and lunch profile on Day 1 prior to administration of studydrug (baseline assessment) and an identical profile on the morning ofDay 5 (on-drug assessment).

Example 2.1: Materials and Methods

Subjects were evaluated for the effects of each treatment on circulatingPYY, GLP-1, glucose, and insulin concentrations over approximately 10hours in response to two standardized meals (˜500 kcal standardizedbreakfast at t=0 min, and ˜1000 kcal standardized lunch at t=300 min)using standard protocols. Metformin pharmacokinetics over anapproximately 11-hour sampling period were also evaluated.

Population: Most randomized subjects were White (79.2%), and half werefemale (50.0%). The mean age was 51.3 years, the mean weight was 93.4kg, and the mean BMI was 33.3 kg/m² at baseline. Nineteen of the 24subjects completed the study.

The primary population for pharmacokinetic and pharmacodynamic analyseswas the Evaluable Population (N=19), defined as all subjects whocompleted all treatment periods consistent with protocol procedures. Theprimary population for safety analyses was the Intent-to-Treat (ITT)Population (N=24), defined as all subjects who received at least onedose of study medication.

Formulations

The metformin DR formulation was a US-supplied commercially availablefilm-coated immediate-release tablet containing 500 mg metforminhydrochloride, to which additional coatings (a seal coating and anenteric coating) were applied in order to delay release of the drug inthe GI tract until the tablet reaches a pH 6.5 region of the distalsmall intestine. The tablets are white, biconvex, circular-shaped coatedtablets, each containing 500 mg metformin hydrochloride. Inactiveingredients in the commercially available tablet included povidone,magnesium stearate, hypromellose, and polyethylene glycol. Inactiveingredients in the additional Eleelyx coating systems includedhypromellose, triacetin, talc, methacrylic acid copolymer (Eudragit® L30D-55), poly(methyl acrylate-co-methyl methacrylate-co-methacrylic acid)7:3:1 (Eudragit® FS 30 D), sodium lauryl sulfate, polysorbate 80,glyceryl monostearate, and triethyl citrate.

The metformin IR formulation was the identical US-supplied commerciallyavailable film-coated immediate-release tablet containing 500 mgmetformin hydrochloride, to which only the additional seal coating isapplied. No delayed-release (enteric) coating was applied. Inactiveingredients in the additional seal coating system included hypromellose,triacetin and talc.

The metformin formulations were supplied to the site as bulk tabletspackaged in screw cap containers labeled with container number and lotnumber. All study medications were stored in cool and dry conditions asindicated on the label, and used only as directed by study personnel.Study medication was dispensed by the unblinded site pharmacist or studypersonnel according to the randomization scheme at the beginning of eachtreatment period.

Administration

Study medication was administered orally as intact tablets (swallowedwhole) with water at the beginning of the breakfast and dinner meals.Subjects self-administered their assigned study medications on theevening of Day 1 through the morning of Day 4 according to instructionsprovided on Day 1 by the study site staff. The last two doses of studymedication for each treatment period (evening of Day 4 and morning ofDay 5) were administered to subjects by qualified study site personnel.In order to reduce gastrointestinal side effects, all treatment regimensinitiated treatment at 500 mg/dose for the first 3 doses, followed by anincrease to the randomized dose (500 mg/dose, 1000 mg, or 1500 mg/dose)for the remainder of the study period. Study site personnel contactedsubjects by telephone on the second day of dosing of each treatmentperiod to assess compliance and adverse events through non-directedquestioning and to remind them to dose-escalate if appropriate.

Example 2.2: Results Pharmacokinetic Evaluations

Pharmacokinetic Profiles

FIG. 8 presents the mean plasma metformin concentrations at Day 5 bytreatment and time point. On Day 5, the pre-dose mean concentration ofMetformin IR at t=0 was 350 ng/mL, which is consistent with steady-statetrough concentrations published in the literature. After theadministration of Metformin IR at t=−1 minute, there was a rapidincrease in metformin concentrations that peaked at 1249 ng/mL 90 minafter the dose followed by a steady decline for the remainder of thesampling period.

The pre-dose concentrations for both doses of Metformin DR wereapproximately 2 times higher than those for Metformin IR (716 ng/mL for1000 mg DR and 602 ng/mL for 500 ng/mL DR vs. 350 ng/dL for 1000 mg IR).Following the administration of both doses of metformin DR at t=−1minute, there was a decrease in metformin concentrations for the first240 minutes followed by a small rise in metformin concentrations afterthe standardized lunch meal, which then plateaued for the remainder ofthe sampling period. The entire 11-hour metformin profiles remainedbelow the pre-dose concentrations measured at t=0. The absorptionprofiles for Metformin DR dosing with the evening meal were slowedrelative to doses administered with the breakfast meal, consistent withslowed intestinal transit during the sleeping hours. Metformin DRconcentrations for the 500-mg dose were lower than the 1000-mg dose atall time points although the reductions were less thandose-proportional. This observation is consistent with the lack ofdose-proportionality reported for Metformin IR and could be due to asaturable absorption process in the gut.

The Metformin DR+Metformin IR treatment group had the highest pre-doseconcentrations of the four treatment groups (761 ng/mL). Following theadministration of study medication at t=−1 minute, metforminconcentrations rapidly rose in a manner similar to metformin IR butgenerally remained below the Metformin IR concentration curve for thefirst 500 minutes. For the remainder of the sampling period,concentrations plateaued but where higher than those observed with theother treatments.

Pharmacokinetic Parameters

Table 7 and FIG. 9 present the relative bioavailability of metformin bytreatment versus Metformin IR at Day 5. Compared to the Metformin IRformulation the metformin exposure from t=0 to time of lastconcentration after study medication administration (AUC_(0-t)) wasstatistically significantly reduced by 45.2% with 1000 mg Metformin DR(% mean ratio of 54.8; p<0.0001) and 56.6% with 500 mg Metformin DR (%mean ratio of 43.4; p<0.0001). Compared to Metformin IR, C_(max) wasalso was statistically significantly reduced by 34.9% with 1000 mgMetformin DR (% mean ratio of 65.1; p<0.0001) and 47.7% with 500 mgmetformin DR (% mean ratio of 52.3; p<0.0001).

The Metformin DR+IR treatment resulted in exposures similar to that ofthe 1000 mg Metformin IR (% mean ratio of 90.9; p=0.2271) despite anincrease in daily dose of 50%.

TABLE 7 Relative Bioavailability of Metformin by Treatment versusMetformin IR at Day 5 - Evaluable Population 500 mg Met 1000 mg 1000 mg500 mg IR + 1000 mg Met IR Met DR Met DR Met DR Statistic (N = 19) (N =19) (N = 19) (N = 19) AUC_(0-t) (ng * h/mL) Geometric LS mean 8325 45593614 7567 % ratio [1] Geometric LS mean NA 54.8 43.4 90.9 90% CI NA48.1, 62.4 38.1, 49.5 79.8, 103.6 p value NA <0.0001 <0.0001 0.2271Cmax_(0-t) (ng/mL) Geometric LS mean 1283 836 671 1150 % ratio [1]Geometric LS mean NA 65.1 52.3 89.6 90% CI of % ratio NA 56.5, 75.045.4, 60.3 77.8, 103.3 p value of % ratio NA <0.0001 <0.0001 0.2016Abbreviations: NA = not applicable; t = last quantifiable concentrationfollowing dose administration. Note: Intra subject CV % was 24.2 forAUC_(0-t) and 26.3 for C_(max). [1] (1000 mg Met IR, 1000 mg Met DR, or500 mg Met DR)/1000 mg Met IR.

Pharmacodynamic Evaluations

PYY Total

FIG. 10 and Table 8 present the mean plasma PYY total concentrationprofiles at baseline and Day 5 by treatment and time point and thecorresponding analysis of pharmacodynamic parameters, respectively.Baseline plasma PYY total concentrations were similar between treatmentsat most time points. Additionally, all metformin treatmentsstatistically significantly increased PYY total exposure and peakconcentrations (p<0.01 for all), with percent ratios (Day5/Day1) forAUC_(0-t) and Cmax ranging from 1.26 to 1.55. Fasting plasma PYY totalconcentrations were also statistically significantly increased frombaseline at Day 5 for each treatment (Table 9, p<0.01 for all). Theseresults indicate that all of the treatments studied elicited similar PYYtotal responses to two standardized meals.

TABLE 8 Pharmacodynamic Analysis of Plasma PYY Total (pg/mL) -Within-Treatment Comparison Based on Ratios - Evaluable Population 500mg Met IR + 1000 mg Met IR 1000 mg Met DR 500 mg Met DR 1000 mg Met DRStatistic (N = 19) (N = 19) (N = 19) (N = 19) AUC_(0-t) (pg/mL * min) BLgeo. LS mean (SE) 51487 (5104) 51518 (5579) 50932 (5587) 51985 (5614)EOT geo. LS mean (SE) 79654 (7897) 71218 (7712) 74546 (8178) 77270(8344) % ratio [1] Geo. LS mean (SE)  1.55 (0.09)  1.38 (0.09)  1.46(0.06)  1.49 (0.06) 95% CI 1.36, 1.75 1.22, 1.57 1.34, 1.59 1.36, 1.62 pvalue <0.0001 <0.0001 <0.0001 <0.0001 Cmax_(0-t) (pg/mL) BL geo. LS mean(SE) 124 (13) 135 (16) 122 (13) 129 (15) EOT geo. LS mean (SE) 190 (19)169 (20) 169 (18) 184 (21) % ratio [1] Geo. LS mean (SE)  1.53 (0.10) 1.26 (0.09)  1.38 (0.08)  1.43 (0.06) 95% CI 1.34, 1.75 1.08, 1.471.23, 1.55 1.31, 1.56 p value <0.0001  0.0056 <0.0001 <0.0001Abbreviations: BL = baseline (Day 1); EOT = end of treatment (Day 5);geo. = geometric; t = last quantifiable concentration following doseadministration. [1] EOT (Day 5)/BL (Day 1) for each treatment

TABLE 9 Fasting Plasma PYY Total (pg/mL) at Baseline and Day 5 -Evaluable Population 500 mg Met IR + 1000 mg Met IR 1000 mg Met DR 500mg Met DR 1000 mg Met DR Statistic (N = 19) (N = 19) (N = 19) (N = 19)BL LS mean (SE) 59.47 (10.22) 56.26 (8.32) 53.39 (11.42) 59.11 (12.90)EOT LS mean (SE) 94.75 (10.22) 75.80 (8.32) 91.13 (11.42) 92.92 (12.90)LS mean diff (SE) 35.28 (6.64)  19.53 (6.17) 37.73 (10.41) 33.81 (9.91) 95% CI 21.28, 49.28 6.51, 32.56 15.77, 59.69 12.90, 54.71 p value <.00010.0057 0.0021 0.0033 Abbreviations: BL = baseline (Day 1); EOT = end oftreatment (Day 5).

GLP-1 Active

FIG. 11 and Table 10 present the mean plasma GLP-1 active concentrationprofiles at baseline and Day 5 by treatment and time point and thecorresponding analysis of pharmacodynamic parameters, respectively.Baseline plasma GLP-1 active concentrations were similar betweentreatments at most time points. Additionally, all metformin treatmentsstatistically significantly increased GLP-1 active exposure and peakconcentrations (p<0.01 for all), with percent ratios (Day5/Day1) forAUC0-t and Cmax ranging from 1.42 to 1.88. Fasting plasma GLP-1 totalconcentrations were also statistically significantly increased frombaseline at Day 5 for each treatment (Table 11, p<0.05 for all). Theseresults indicate that all of the treatments studied elicited similarGLP-1 active responses to two standardized meals.

TABLE 10 Pharmacodynamic Analysis of Plasma GLP-1 Active (pmol/L) -Within-Treatment Comparison Based on Ratios - Evaluable Population 500mg Met IR + 1000 mg Met IR 1000 mg Met DR 500 mg Met DR 1000 mg Met DRStatistic (N = 19) (N = 19) (N = 19) (N = 19) AUC_(0-t) (pmol/L * min)BL geo. LS mean (SE) 3031 (386) 3059 (405) 3547 (447) 3277 (380) EOTgeo. LS mean (SE) 5655 (719) 4953 (655) 5993 (755) 6158 (714) % ratio[1] Geo. LS mean (SE)  1.87 (0.18)  1.62 (0.11)  1.69 (0.15)  1.88(0.19) 95% CI 1.52, 2.29 1.40, 1.87 1.41, 2.03 1.52, 2.33 p value<0.0001 <0.0001 <0.0001 <0.0001 Cmax_(0-t) (pmol/L) BL geo. LS mean (SE)11.3 (1.4) 10.6 (1.3) 13.9 (1.5) 12.0 (1.3) EOT geo. LS mean (SE) 19.2(2.3) 17.3 (2.1) 19.7 (2.1) 21.1 (2.3) % ratio [1] Geo. LS mean (SE) 1.70 (0.16)  1.64 (0.17)  1.42 (0.14)  1.76 (0.19) 95% CI 1.40, 2.071.32, 2.03 1.15, 1.76 1.40, 2.21 p value <0.0001  0.0001  0.0025 <0.0001Abbreviations: BL = baseline (Day 1); EOT = end of treatment (Day 5);geo. = geometric; t = last quantifiable concentration following doseadministration. [1] EOT (Day 5)/BL (Day 1) for each treatment.

TABLE 11 Fasting Plasma GLP-1 Active (pmol/L) at Baseline and Day 5 -Evaluable Population 1000 mg 1000 mg 500 mg 500 mg Met IR + Met IR MetDR Met DR 1000 mg Met DR Statistic (N = 19) (N = 19) (N = 19) (N = 19)BL LS 3.79 (1.16) 3.93 (1.19) 4.73 (1.31) 3.69 (1.04) mean (SE) EOT LS6.32 (1.16) 5.10 (1.19) 6.62 (1.31) 5.64 (1.04) mean (SE) LS mean 2.53(0.83) 1.17 (0.54) 1.89 (0.45) 1.95 (0.91) diff (SE) 95% CI 0.80, 4.260.03, 2.31 0.96, 2.83 0.03, 3.87 p value 0.0067 0.0444 0.0005 0.0466Abbreviations: BL = baseline (Day 1); EOT = end of treatment (Day 5).

Glucose

FIG. 12 and Table 12 present mean plasma glucose concentration profilesat baseline and Day 5 by treatment and timepoint and the correspondingpharmacodynamic parameters by meal, respectively.

Baseline plasma glucose concentrations were similar between treatmentsat most time points. Additionally, all metformin treatmentsstatistically significantly decreased glucose exposure and peakconcentrations for both meal intervals to a similar extent (p<0.001 forall).

TABLE 12 Pharmacodynamic Analysis of Plasma Glucose (mg/dL) by MealInterval - Within-Treatment Comparison Based on Ratios - EvaluablePopulation 500 mg Met IR + 1000 mg Met IR 1000 mg Met DR 500 mg Met DR1000 mg Met DR Statistic (N = 19) (N = 19) (N = 19) (N = 19) BreakfastInterval AUC_(0-t295) (mg/dL * min) BL geo. LS mean (SE) 66642 (5480)66257 (5815) 65755 (5906) 66507 (5617) EOT geo. LS mean (SE) 57007(4688) 59269 (5201) 60346 (5420) 56658 (4785) % ratio [1] Geo. LS mean(SE)  0.86 (0.02)  0.90 (0.02)  0.92 (0.01)  0.85 (0.02) 95% CI 0.81,0.91 0.86, 0.93 0.89, 0.95 0.81, 0.90 p value <0.0001 <0.0001 <0.0001<0.0001 Cmax_(0-t295) (mg/dL) BL geo. LS mean (SE) 291 (21) 290 (22) 292(24) 290 (20) EOT geo. LS mean (SE) 255 (19) 261 (20) 263 (21) 248 (17)% ratio [1] Geo. LS mean (SE)  0.88 (0.02)  0.90 (0.02)  0.90 (0.01) 0.85 (0.02) 95% CI 0.83, 0.92 0.86, 0.95 0.88, 0.93 0.81, 0.90 p value<0.0001 0.0004 <0.0001 <0.0001 Lunch Interval AUC_(t295-t) (pg/mL * min)BL geo. LS mean (SE) 76286 (6051) 75132 (6199) 74566 (6634) 74799 (5972)EOT geo. LS mean (SE) 65558 (5200) 66330 (5473) 68480 (6093) 63495(5070) % ratio [1] Geo. LS mean (SE)  0.86 (0.02)  0.88 (0.02)  0.92(0.02)  0.85 (0.03) 95% CI 0.82, 0.91 0.85, 0.92 0.88, 0.95 0.79, 0.91 pvalue <0.0001 <0.0001 0.0002 0.0001 Cmax_(t295-t) (pg/mL) BL geo. LSmean (SE) 295 (22) 288 (21) 287 (23) 293 (22) EOT geo. LS mean (SE) 250(19) 255 (19) 265 (22) 245 (19) % ratio [1] Geo. LS mean (SE)  0.85(0.03)  0.89 (0.02)  0.93 (0.02)  0.84 (0.03) 95% CI 0.80, 0.90 0.85,0.92 0.89, 0.96 0.78, 0.90 p value <0.0001 <0.0001 0.0002 <0.0001Abbreviations: BL = baseline (Day 1); EOT = end of treatment (Day 5); t= last quantifiable concentration following dose administration. [1] EOT(Day 5)/BL (Day 1) for each treatment.

Table 13 presents the pharmacodynamic parameters for glucose from t=0 totime of last concentration after study medication administration.Consistent with the pharmacodynamic parameters for the breakfast andlunch intervals, all metformin treatments statistically significantlydecreased glucose exposure and peak concentrations (p<0.001 for all),with percent ratios (Day5/Day1) for AUC_(0-t) and Cmax ranging from 0.84to 0.92.

TABLE 13 Pharmacodynamic Analysis of Plasma Glucose (mg/dL) and Insulin(pmol/L) - Within-Treatment Comparison Based on Ratios - EvaluablePopulation 500 mg Met IR + 1000 mg Met IR 1000 mg Met DR 500 mg Met DR1000 mg Met DR Statistic (N = 19) (N = 19) (N = 19) (N = 19) GlucoseAUC_(0-t) (mg/dL * min) BL geo. LS mean (SE) 143041 (11408) 141572(11884) 140503 (12403) 141502 (11477) EOT geo. LS mean (SE) 122748(9789)  125742 (10556) 129029 (11390) 120255 (9754)  % ratio [1] Geo. LSmean (SE)  0.86 (0.02)  0.89 (0.01)  0.92 (0.01)  0.85 (0.02) 95% CI0.82, 0.90 0.86, 0.92 0.89, 0.95 0.80, 0.90 p value <0.0001 <0.0001<0.0001 <0.0001 Cmax_(0-t) (mg/dL) BL geo. LS mean (SE) 301 (22) 301(22) 301 (24) 304 (22) EOT geo. LS mean (SE) 265 (19) 269 (19) 277 (22)256 (19) % ratio [1] Geo. LS mean (SE)  0.88 (0.03)  0.89 (0.02)  0.92(0.01)  0.84 (0.02) 95% CI 0.83, 0.93 0.86, 0.93 0.90, 0.95 0.79, 0.90 pvalue 0.0002 <0.0001 <0.0001 <0.0001 Insulin AUC_(0-t) (pmol/L * min) BLgeo. LS mean (SE) 191826 (26987) 176384 (30776) 199339 (28758) 191204(26683) EOT geo. LS mean (SE) 186379 (26145) 175190 (30567) 194650(28049) 184975 (25814) % ratio [1] Geo. LS mean (SE)  0.97 (0.05)  0.99(0.04)  0.98 (0.03)  0.97 (0.04) 95% CI 0.88, 1.08 0.92, 1.08 0.91, 1.040.89, 1.05 p value 0.5587 0.8622 0.4551 0.4070 Cmax_(0-t) (pmol/L) BLgeo. LS mean (SE) 594 (88) 664 (112) 604 (96) 598 (92) EOT geo. LS mean(SE) 539 (80) 586 (99)  578 (92) 539 (83) % ratio [1] Geo. LS mean (SE) 0.91 (0.06)  0.88 (0.09)  0.96 (0.06)  0.90 (0.06) 95% CI 0.79, 1.040.72, 1.08 0.85, 1.08 0.79, 1.03 p value 0.1462 0.2167 0.4649 0.1110Abbreviations: BL = baseline (Day 1); EOT = end of treatment (Day 5); t= last quantifiable concentration following dose administration. [1] EOT(Day 5)/BL (Day 1) for each treatment.

Table 14 presents the LS mean (SE) and FIG. 13 presents the individualchange in fasting plasma glucose concentrations from baseline to Day 5by treatment. Baseline fasting glucose concentrations were similar andranged from 196 mg/dL to 200 mg/dL among the treatment groups. Alltreatment groups achieved statistically significant reductions (p<0.01for all) in fasting plasma glucose after 5 days of treatment. As shownin FIG. 13 , the LSM and distribution of individual responses weresimilar between treatment groups.

TABLE 14 Fasting Plasma Glucose (mg/dL) at Baseline and Day 5 -Evaluable Population 1000 mg 1000 mg 500 mg 500 mg Met IR + Met IR MetDR Met DR 1000 mg Met DR Statistic (N = 19) (N = 19) (N = 19) (N = 19)BL LS 200.3 (16.2) 197.0 (16.7) 198.7 (17.4) 195.9 (15.4) mean (SE) EOTLS 177.8 (16.2) 177.1 (16.7) 182.2 (17.4) 174.7 (15.4) mean (SE) LS mean−22.5 (6.8)  −19.9 (5.0)  −16.4 (3.8)  −21.2 (4.7)  diff (SE) 95% CI−36.8, −8.16 −30.5, −9.3 −24.5, −8.4 −31.1, −11.2 p value 0.0040 0.00090.0004 0.0003 Abbreviations: BL = baseline (Day 1); EOT = end oftreatment (Day 5).

Insulin

Tables 15 and 16 present the pharmacodynamic parameters for insulin andbaseline and Day 5 fasting plasma insulin concentrations, respectively.There were no statistically significant changes in insulin exposure,peak concentrations, or fasting concentrations for any of the treatments(p>0.05 for all). Maintenance of insulin concentrations despite thelower circulating glucose concentrations is indicative of an incretineffect.

TABLE 15 Pharmacodynamic Analysis of Insulin (pmol/L) - Within-TreatmentComparison Based on Ratios - Evaluable Population 500 mg Met IR + 1000mg Met IR 1000 mg Met DR 500 mg Met DR 1000 mg Met DR Statistic (N = 19)(N = 19) (N = 19) (N = 19) AUC_(0-t) (pmol/L * min) BL geo. LS mean (SE)191826 (26987) 176384 (30776) 199339 (28758) 191204 (26683) EOT geo. LSmean (SE) 186379 (26145) 175190 (30567) 194650 (28049) 184975 (25814) %ratio [1] Geo. LS mean (SE)  0.97 (0.05)  0.99 (0.04)  0.98 (0.03)  0.97(0.04) 95% CI 0.88, 1.08 0.92, 1.08 0.91, 1.04 0.89, 1.05 p value 0.55870.8622 0.4551 0.4070 Cmax_(0-t) (pmol/L) BL geo. LS mean (SE) 594 (88)664 (112) 604 (96) 598 (92) EOT geo. LS mean (SE) 539 (80) 586 (99)  578(92) 539 (83) % ratio [1] Geo. LS mean (SE)  0.91 (0.06)  0.88 (0.09) 0.96 (0.06)  0.90 (0.06) 95% CI 0.79, 1.04 0.72, 1.08 0.85, 1.08 0.79,1.03 p value 0.1462 0.2167 0.4649 0.1110 Abbreviations: BL = baseline(Day 1); EOT = end of treatment (Day 5); t = last quantifiableconcentration following dose administration. [1] EOT (Day 5)/BL (Day 1)for each treatment.

TABLE 16 Fasting Insulin (pmol/L) at Baseline and Day 5 - EvaluablePopulation 1000 mg 1000 mg 500 mg 500 mg Met IR + Met IR Met DR Met DR1000 mg Met DR Statistic (N = 19) (N = 19) (N = 19) (N = 19) BL LS 183.8(42.3) 187.7 (29.0) 166.7 (34.5) 169.8 (29.9) mean (SE) EOT LS 151.9(42.3) 138.1 (29.0) 157.8 (34.5) 147.0 (29.9) mean (SE) LS mean −31.8(30.8) −49.6 (18.1)  −8.8 (13.2) −22.8 (8.6)  diff (SE) 95% CI −96.5,32.8 −87.7, −11.6 −36.6, 18.9 −40.8, −4.8 p value 0.3146 0.0135 0.51090.0160 Abbreviations: BL = baseline (Day 1); EOT = end of treatment (Day5).

Safety Evaluations

Table 17 summarizes treatment-emergent adverse events by SOC, preferredterm, and most recent treatment at onset.

Consistent with the metformin prescribing information, adverse eventswere primarily gastrointestinal in nature with nausea, vomiting, andretching occurring only in the treatment groups receiving Metformin IRwith or without Metformin DR. Diarrhea was reported across all treatmentgroups and appeared to be dose-dependent with the greatest incidencewith Metformin IR+Metformin DR (7 subjects, 33.3%) and the lowestincidence with the lowest dose of Metformin DR (2 subjects, 10.0%). Ofnote, all gastrointestinal events in the 500 mg Metformin DR groupoccurred during the post-treatment washout period while off study drug.Nervous system disorders such as dizziness and headache were also morefrequent with Metformin IR than either DR dosage. Overall, fewergastrointestinal and nervous system disorder adverse events werereported with the Metformin DR than metformin IR, indicating that thereduced systemic exposure to metformin achieved by bypassing theproximal small intestine improved tolerability.

TABLE 17 Summary of Treatment-Emergent Adverse Events by SOC andPreferred Term and Treatment at Onset - ITT Population 500 mg Met IR +1000 mg Met IR 1000 mg Met DR 500 mg Met DR 1000 mg Met DR SOC (N = 22)(N = 20) (N = 20) (N = 21) Preferred Term n (%) n (%) n (%) n (%) AnyTEAE 6 (27.3) 5 (25.0) 4 (20.0) 10 (47.6) Gastrointestinal 5 (22.7) 3(15.0) 2 (10.0) 8 (38.1) Disorders Abdominal Discomfort 0 (0) 0 (0) 0(0) 1 (4.8) Abdominal Distension 0 (0) 0 (0) 0 (0) 1 (4.8) AbdominalPain 0 (0) 0 (0) 1 (5.0) 1 (4.8) Diarrhea 3 (13.6) 3 (15.0) 2 (10.0) 7(33.3) Dyspepsia 1 (4.5) 0 (0) 1 (5.0) 1 (4.8) Frequent Bowel 0 (0) 0(0) 0 (0) 1 (4.8) Movements Nausea 2 (9.1) 0 (0) 0 (0) 3 (14.3) Retching1 (4.5) 0 (0) 0 (0) 0 (0) Vomiting 2 (9.1) 0 (0) 0 (0) 0 (0) GeneralDisorders And 0 (0) 0 (0) 1 (5.0) 0 (0) Administration Site ConditionsFatigue 0 (0) 0 (0) 1 (5.0) 0 (0) Infections And 0 (0) 0 (0) 0 (0) 1(4.8) Infestations Oral Herpes 0 (0) 0 (0) 0 (0) 1 (4.8) Investigations0 (0) 0 (0) 0 (0) 1 (4.8) Weight Decreased 0 (0) 0 (0) 0 (0) 1 (4.8)Musculoskeletal And 0 (0) 1 (5.0) 0 (0) 0 (0) Connective TissueDisorders Pain In Extremity 0 (0) 1 (5.0) 0 (0) 0 (0) Neoplasms Benign,0 (0) 1 (5.0) 0 (0) 0 (0) Malignant And Unspecified (Incl Cysts AndPolyps) Gastrointestinal 0 (0) 1 (5.0) 0 (0) 0 (0) Stromal TumourNervous System 5 (22.7) 1 (5.0) 1 (5.0) 0 (0) Disorders Dizziness 3(13.6) 0 (0) 0 (0) 0 (0) Headache 2 (9.1) 1 (5.0) 1 (5.0) 0 (0) SinusHeadache 1 (4.5) 0 (0) 0 (0) 0 (0) Renal And Urinary 0 (0) 0 (0) 0 (0) 1(4.8) Disorders Pollakiuria 0 (0) 0 (0) 0 (0) 1 (4.8) Skin And 0 (0) 0(0) 0 (0) 1 (4.8) Subcutaneous Tissue Disorders Hyperhidrosis 0 (0) 0(0) 0 (0) 1 (4.8)

Example 2.3: Discussion

In this study, metformin concentrations in plasma were measured over 11hours at steady-state on the 5th day (FIG. 1 ) of BID dosing(pre-breakfast and pre-supper) with 1000 mg immediate-release metformin(Metformin IR), 500 mg Metformin DR and 1000 mg Metformin DR, or acombination of 500 mg Metformin IR and 1000 mg Metformin DR. Allsubjects had type 2 diabetes and received each treatment in a randomizedcrossover design with a one week washout between treatments.

The observed profiles indicated lower circulating amounts of metforminwhen using the Metformin DR compared to Metformin IR. The Day 5 pre-doseconcentration of metformin with Metformin IR on the morning of Day 5 was350 ng/mL, which is consistent with steady-state trough concentrationspublished in the literature. After the administration of Metformin IR onthe morning of Day 5, there was a rapid increase in metforminconcentration that peaked 90 min after the dose followed by a steadydecline for the remainder of the sampling period.

With Metformin DR dosing, the highest concentration of metformin wasobserved prior to the dose on the morning of Day 5, which wasapproximately 2 times higher at that time point than those for MetforminIR. Following administration of either dose of Metformin DR, there was adecrease in metformin concentration for the first 240 minutes followedby a small rise in metformin concentration at 360 minutes, whichplateaued for the remainder of the sampling period. The entire 11-hourMetformin DR PK profiles remained below the pre-dose concentrationsmeasured at t=0. These results indicate that the absorption profiles forMetformin DR dosing with the evening meal were slowed relative to dosesadministered with the breakfast meal, consistent with slowed intestinaltransit during the sleeping hours. Thus, concentrations throughout thefirst 240 minutes of the Day 5 profile were predominantly a result ofabsorption from the Day 4 evening dose and concentrations from 240minutes through 660 mins were predominantly a result of absorption fromthe Day 5 morning dose.

Example 3: Analysis of Pharmacokinetic Differences Between Morning andEvening Dosing

To better characterize the pharmacokinetic differences between morningand evening doses, the study of Example 3 was designed to obtain 36-hourPK profiles of Metformin DR at doses of 500 and 1000 mg given at theevening and breakfast meals in healthy subjects. Subjects also received1000 mg Metformin IR with the evening and breakfast meals and 2000 mgmetformin extended-release (Metformin XR) with the evening meal duringseparate treatment periods. All subjects received each treatment in arandomized crossover design with a one week washout between treatments.

The metformin DR formulation was a US-supplied commercially availablefilm-coated immediate-release tablet containing 500 mg metforminhydrochloride, to which additional coatings (a seal coating and anenteric coating) were applied in order to delay release of the drug inthe GI tract until the tablet reaches a pH 6.5 region of the distalsmall intestine. The tablets are white, biconvex, circular-shaped coatedtablets, each containing 500 mg metformin hydrochloride. Inactiveingredients in the commercially available tablet included povidone,magnesium stearate, hypromellose, and polyethylene glycol. Inactiveingredients in the additional coating systems included hypromellose,triacetin, talc, methacrylic acid copolymer (Eudragit® L30 D-55),poly(methyl acrylate-co-methyl methacrylate-co-methacrylic acid) 7:3:1(Eudragit® FS 30 D), sodium lauryl sulfate, polysorbate 80, glycerylmonostearate, and triethyl citrate. The metformin IR and metformin XRformulations were commercially available formulations (Aurobindo PharmaLimited and Bristol-Myers Squibb respectively) without any modification.

As shown in FIG. 14 , both doses of Metformin DR resulted insubstantially less systemic metformin than was observed with eitherMetformin IR or Metformin XR. Of note, the total plasma metforminexposure as measured by AUC of 1000 mg Metformin IR BID and 2000 mgMetformin XR QD (total daily doses of 2000 mg) were very similar,consistent with the previously established bioequivalence between thetwo formulations. The Metformin DR profile over the first 12 hoursshowed that there is a delay in systemic absorption of Metformin DR,with the first quantifiable plasma concentration occurring approximately6-7 hours after the dose. The highest concentration was achievedapproximately 11 hours after the evening dose. After a second dose withMetformin DR in the morning, the plasma concentration of metformindecreased until approximately 15 h post first dose, followed by a smallrise corresponding to approximately 3 hours after the second dose.

As noted above, the data indicate that Metformin IR and both doses ofMetformin DR have slightly greater bioavailability after an evening dosethan the morning dose, perhaps as a result of slower intestinal transitduring the sleeping hours.

Table 18 shows the Mean (CV %) plasma pharmacokinetic parameters ofmetformin following oral administration of each treatment and FIG. 15compares the mean (SEM) values of C_(max) (left panel) and AUC_(0-36 hr)(right panel). Both doses of Metformin DR resulted in substantialreductions in exposure as well as a delay in absorption of 6-7 hours.

TABLE 18 Mean (CV %) Plasma Pharmacokinetic Parameters of MetforminFollowing Oral Administration of Treatment A, B, C, and D - EvaluablePopulation 1000 mg Met IR 500 mg Met DR BID 1000 mg Met DR BID 2000 mgMet XR QD PK Parameters BID (Treatment A) (Treatment B) (Treatment C)(Treatment D) N 19 19 19 19 AUC₀₋₂₄ 17361 (24.3) 5541 (31.9) 7634 (31.9)16406 (24.5) (ng * h/mL) AUC_(0-t) 18709 (24.3) 6164 (32.9) 9014 (29.5)16989 (24.8) (ng * h/mL) AUC_(0-∞) 19423 (23.6) 6690 (30.4)^(b) 10277(25.6)^(b) 17398 (24.7) (ng * h/mL) C_(max) 1328 (20.6) 607 (24.0) 905(26.8) 1688 (25.0) (ng/mL) t_(max) ^(a) 15.0 (4.00, 16.0) 11.0 (6.02,19.0) 11.0 (7.00, 19.0) 7.05 (6.00, 11.0) (h) t_(lag) ^(a) 0.00 (0.00,0.500) 6.02 (1.50, 10.0) 7.00 (3.00, 8.00) 0.00 (0.00, 2.00) (h) t_(1/2)8.26 (31.0) 6.19 (49.4)^(b) 11.2 (39.9)^(b) 6.09 (45.5) (h) ^(a)median(min, max) ^(b)n = 18 ^(c)n = 17

Geometric LSM ratios and 90% confidence intervals for the In-transformedC_(max), AUC_(0-t), and AUC_(0-∞) from the Metformin DR treatments (500mg BID [Treatment B] and 1000 mg BID [Treatment C]) relative to theMetformin IR (1000 mg BID [Treatment A]) are shown in Table 19 and therelative bioavailability is plotted in the left panel of FIG. 16 . Theseresults indicate that the rate and extent of exposure (C_(max),AUC_(0-t) and AUC_(0-∞)) from 500 mg BID Metformin DR were approximately55%, 68% and 67% lower, respectively, than those from 1000 mg BIDMetformin IR. At 1000 mg BID Metformin DR (Treatment C, total daily doseof 2000 mg metformin) the rate and extent of exposure (C_(max),AUC_(0-t) and AUC_(0-∞)) were approximately 33%, 52% and 47% lower,respectively, than those from 1000 mg BID Metformin IR (Treatment A,total daily dose of 2000 mg metformin). Similar reductions in the rateand extent of exposure were observed when 500 mg BID and 1000 mg BID ofMetformin DR were compared to 2000 mg QD of Metformin XR (Table 20; FIG.16 , right panel).

TABLE 19 Relative Bioavailability of Metformin Following OralAdministration of 500 mg BID and 1000 mg BID Metformin DR Treatmentcompared to 1000 mg BID Metformin IR-Evaluable Population GeometricLeast-Square % Ratio of LSmeans PK Means (90% CI) p-value Parameter A BC B/A C/A B/A C/A AUC_(0-t) 18116 5816 8611 32.1 47.5 SS SS (ng*h/mL)(29.30-35.18) (43.38-52.09) AUC_(0-∞) 19981 6644 10586 33.3 53.0 SS SS(ng*h/mL) (30.37-36.40) (48.36-58.05) C_(max) 1294 586 865 45.3 66.8 SSSS (ng/mL) (40.88-50.13) (60.34-74.00) SS: Statistically significant(p-value < 0.0001) Treatment A: 1000 mg Metformin IR BID (2 × 500 mgmetformin HCl tablets [immediate-release]) Treatment B: 500 mg MetforminDR BID (1 × 500 mg metformin HCl tablet [delayed-release pH 6.5enteric-coated]) Treatment C: 1000 mg Metformin DR BID (2 × 500 mgmetformin HCl tablets [delayed-release pH 6.5 enteric-coated])

TABLE 20 Relative Bioavailability of Metformin Following OralAdministration of 500 mg BID and 1000 mg BID Metformin DR Treatmentcompared to 2000 mg QD Metformin XR-Evaluable Population PK GeometricLeast- % Ratio of LSmeans Param- Square Means (90% CI) p-value eter B CD B/D C/D B/D C/D AUC_(0-t) 5816 8611 16450 35.4 52.3 SS SS (ng*h/(32.27- (47.77- mL) 38.74) 57.36) AUC_(0-∞) 6644 10586 17873 37.2 59.2SS SS (ng*h/ (33.93- (54.10- mL) 40.73) 64.84) C_(max) 586 865 1631 35.953.0 SS SS (ng/ (32.43- (47.88- mL) 39.77) 58.71) SS: Statisticallysignificant (p-value < 0.0001) Treatment B: 500 mg Metformin DR BID (1 ×500 mg metformin HCl tablet [delayed-release pH 6.5 enteric-coated])Treatment C: 1000 mg Metformin DR BID (2 × 500 mg metformin HCl tablets[delayed-release pH 6.5 enteric-coated]) Treatment D: 2000 mg MetforminXR QD (4 × 500 mg metformin HCl tablets [extended-release])

Taken together, the pharmacokinetic results of Examples 2 and 3 indicatethat delivery of metformin to the lower bowel by administering MetforminDR reduces 24 hour bioavailability by approximately 50% relative toMetformin IR and Metformin XR at the same daily dose. Greater reductionsin exposure were observed when the Metformin DR dose was reduced from atotal daily dose of 2000 mg to 1000 mg, without a reduction in efficacy.In addition, the time of Metformin DR dosing (with the morning orevening meals) meaningfully affected the timing of metformin release inthe intestine (3 vs. 6-7 hours post-dose, respectively) and provides anexplanation for the observation from the study in Example 2 that, theMetformin DR trough values observed prior to the morning dose werehigher than the trough values observed 12 hours after the morning dose.

In the Example 2 study, while the systemic exposure to metformin wassubstantially reduced with Metformin DR (45% with 2000 mg/day and ˜60%with 1000 mg/day, relative to 2000 mg/day of Metformin IR), the fullglucose lowering effects of Metformin IR (2000 mg/day) were maintained.Given that the full glucose lowering effect was observed at both 2000 mgand 1000 mg daily of Metformin DR, lower doses are viable, allowing formore elegant dosage forms than are currently available with existingproducts (Metformin IR and Metformin XR (i.e., smaller tablets, fullyeffective fixed dose combinations, once daily dosing). Moreover, unlikeMetformin IR, Metformin DR was not associated with any nausea andvomiting at either dose.

All patents and patent publications referred to herein are herebyincorporated by reference.

Certain modifications and improvements will occur to those skilled inthe art upon a reading of the foregoing description. It should beunderstood that all such modifications and improvements have beendeleted herein for the sake of conciseness and readability but areproperly within the scope of the following claims.

1. A method of administering a biguanide compound selected frommetformin, phenformin, buformin, or imeglimin to a patient having agastrointestinal condition, comprising administering a delayed-releaseformulation of the biguanide compound or a salt thereof to the patient,wherein the biguanide compound in said formulation has a bioavailabilityless than 20% of the bioavailability of the biguanide compound in animmediate-release composition having the same amount of the biguanidecompound. 2.-16. (canceled)
 17. The method of claim 1, whereinadministering the formulation to the patient produces a mean plasmaAUC₀₋₃₆ less than about 14,000, 13,000 or 12,000 ng*h/mL when saidformulation is administered at 500 mg twice daily.
 18. The method ofclaim 1, wherein administering the formulation to the patient produces amean C_(max) less than about 800, 700 or 600 ng/mL when said formulationis administered at 500 mg twice daily.
 19. The method of claim 1,wherein the formulation is an oral dosage form configured to release thebiguanide compound to the small intestine, and the formulation comprisesan enteric coating that releases the biguanide compound after an onsetof a pH at or above 5.0 or 5.5.
 20. The method of claim 1, wherein theformulation is an oral dosage form configured to release the biguanidecompound to the distal small intestine, and the formulation comprises anenteric coating that releases the biguanide compound after an onset ofpH at or above 6.0 or 6.5.
 21. The method of claim 19, wherein said oraldosage form further comprises a modified release component for at leasta portion of said biguanide compound. 22.-23. (canceled)
 24. The methodof claim 1, further comprising administering a DPP-IV inhibitor.
 25. Themethod of claim 1, further comprising administering an anti-obesity oranti-diabetes agent.
 26. The method of claim 1, wherein the biguanidecompound in the formulation has a bioavailability less than about 40%,50% or 60% of the bioavailability of the biguanide compound in animmediate-release composition having the same amount of the biguanidecompound.
 27. The method of claim 1, whereby the resulting circulatingplasma concentration of the biguanide compound is below about 1 μg/mL.28. The method of claim 1, wherein said biguanide compound is metforminor a salt thereof.
 29. The method of claim 28, wherein said metformin ora salt thereof is metformin hydrochloride.
 30. The method of claim 1,whereby the resulting circulating plasma concentration of the biguanidecompound is below about 0.5 μg/mL.
 31. The method of claim 1, wherebythe resulting circulating plasma concentration of the biguanide compoundis below about 0.25 μg/mL.
 32. The method of claim 1, whereinadministering the delayed-release formulation of the biguanide compoundcomprises administering the formulation to said patient once a day inthe morning.
 33. The method of claim 32, wherein administering thedelayed-release formulation of the biguanide compound comprisesadministering the formulation with a morning meal.
 34. The method ofclaim 32, wherein administering the delayed-release formulation of thebiguanide compound comprises administering from about 1 mg to about 2000mg of the biguanide compound or a salt thereof.
 35. The method of claim32, wherein administering the delayed-release formulation of thebiguanide compound comprises administering from about 1500 mg to about2000 mg of metformin or imeglimin, or a salt thereof.
 36. The method ofclaim 32, wherein administering the delayed-release formulation of thebiguanide compound comprises administering about 2000 mg of metformin orimeglimin, or a salt thereof.
 37. The method of claim 32, whereinadministering the delayed-release formulation of the biguanide compoundcomprises administering about 1500 mg of metformin or imeglimin, or asalt thereof.
 38. The method of claim 34, wherein the biguanide compoundis metformin or a salt thereof.
 39. The method of claim 35, wherein thebiguanide compound is metformin or a salt thereof.
 40. The method ofclaim 36, wherein the biguanide compound is metformin or a salt thereof.41. The method of claim 37, wherein the biguanide compound is metforminor a salt thereof.
 42. The method of claim 1, wherein saiddelayed-release formulation releases the biguanide compound distal ofthe duodenum, to one or more regions of the intestine.
 43. The method ofclaim 1, wherein said delayed-release formulation releases the biguanidecompound distal of the jejunum, to one or more regions of the intestine.44. The method of claim 1, wherein the gastrointestinal condition isdiarrhea.
 45. The method of claim 1, wherein the gastrointestinalcondition is nausea.
 46. The method of claim 1, wherein thegastrointestinal condition is vomiting.
 47. The method of claim 1,wherein the gastrointestinal condition is dizziness.
 48. The method ofclaim 1, wherein the gastrointestinal condition is headache.
 49. Themethod of claim 1, wherein the gastrointestinal condition is dyspepsia.